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Gainza J, Serrano-Sánchez F, Nemes NM, Dura OJ, Martínez JL, Fauth F, Alonso JA. Strongly reduced lattice thermal conductivity in Sn-doped rare-earth (M) filled skutterudites M x Co 4Sb 12-y Sn y , promoted by Sb-Sn disordering and phase segregation. RSC Adv 2021; 11:26421-26431. [PMID: 35479462 PMCID: PMC9037351 DOI: 10.1039/d1ra04270j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/26/2021] [Indexed: 11/21/2022] Open
Abstract
CoSb3 thermoelectric skutterudite has been filled with rare-earth metals (M = La, Ce, Yb) and partially doped with Sn in specimens of M x Co4Sb12-y Sn y stoichiometry. This has been achieved under high-pressure conditions at 3.5 GPa in a piston-cylinder hydrostatic press. A structural investigation using synchrotron X-ray diffraction data reveals a phase segregation in twin skutterudite phases with filling fraction fluctuation and different unit-cell sizes. As a result of three effects acting as phonon scatterers, namely the rattling effect of M at the wide 8a cages of the cubic Im3̄ structure, the phase segregation, and the intrinsic disorder introduced by Sn substitution at the Sb sublattice, the total thermal conductivity (κ) dramatically falls to reach minimum values under 2 W m-1 K-1, well below those typically exhibited by other thermoelectric materials based upon single-filled skutterudites. The power factor is substantially enhanced to 1.11 mW m-1 K-2 in Yb0.5Co4Sb11.6Sn0.4 with respect to the unfilled composition, as a result of the charge transfer promoted by the filler.
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Affiliation(s)
- J Gainza
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain
| | - F Serrano-Sánchez
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain
| | - N M Nemes
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain
- Departamento de Física de Materiales, Universidad Complutense de Madrid E-28040 Madrid Spain
| | - O J Dura
- Departamento de Física Aplicada, Universidad de Castilla-La Mancha Ciudad Real E-13071 Spain
| | - J L Martínez
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain
| | - F Fauth
- CELLS-ALBA Synchrotron Cerdanyola del Valles Barcelona E-08290 Spain
| | - J A Alonso
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain
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Reales-Calderón JA, Sun Z, Mascaraque V, Pérez-Navarro E, Vialás V, Deutsch EW, Moritz RL, Gil C, Martínez JL, Molero G. A wide-ranging Pseudomonas aeruginosa PeptideAtlas build: A useful proteomic resource for a versatile pathogen. J Proteomics 2021; 239:104192. [PMID: 33757883 PMCID: PMC8668395 DOI: 10.1016/j.jprot.2021.104192] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 11/23/2020] [Revised: 02/17/2021] [Accepted: 03/10/2021] [Indexed: 01/05/2023]
Abstract
Pseudomonas aeruginosa is an important opportunistic human pathogen with high prevalence in nosocomial infections. This microorganism is a good model for understanding biological processes such as the quorum-sensing response, the metabolic integration of virulence, the mechanisms of global regulation of bacterial physiology, and the evolution of antibiotic resistance. Till now, P. aeruginosa proteomic data, although available in several on-line repositories, were dispersed and difficult to access. In the present work, proteomes of the PAO1 strain grown under different conditions and from diverse cellular compartments have been joined to build the Pseudomonas PeptideAtlas. This resource is a comprehensive mass spectrometry-derived peptide and inferred protein database with 71.3% coverage of the total predicted proteome of P. aeruginosa PAO1, the highest coverage among bacterial PeptideAtlas datasets. The proteins included cover 89% of metabolic proteins, 72% of proteins involved in genetic information processing, 83% of proteins responsible for environmental information processing, more than 88% of the ones related to quorum sensing and biofilm formation, and 89% of proteins responsible for antimicrobial resistance. It exemplifies a necessary tool for targeted proteomics studies, system-wide observations, and cross-species observational studies. The manuscript describes the building of the PeptideAtlas and the contribution of the different proteomic data used. SIGNIFICANCE: Pseudomonas aeruginosa is among the most versatile human bacterial pathogens. Studies of its proteome are very important as they can reveal virulence factors and mechanisms of antibiotic resistance. The construction of a proteomic resource such as the PeptideAtlas enables targeted proteomics studies, system-wide observations, and cross-species observational studies.
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Affiliation(s)
- J A Reales-Calderón
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Spain
| | - Z Sun
- Institute for Systems Biology, Seattle, WA, USA
| | - V Mascaraque
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Spain
| | - E Pérez-Navarro
- Unidad de Proteómica de la Universidad Complutense de Madrid, Spain
| | - V Vialás
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Spain
| | - E W Deutsch
- Institute for Systems Biology, Seattle, WA, USA
| | - R L Moritz
- Institute for Systems Biology, Seattle, WA, USA
| | - C Gil
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Spain; Unidad de Proteómica de la Universidad Complutense de Madrid, Spain
| | - J L Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - G Molero
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Spain.
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Rivera MA, Fahey TD, López-Taylor JR, Martínez JL. The Association of Aquaporin-1 Gene with Marathon Running Performance Level: a Confirmatory Study Conducted in Male Hispanic Marathon Runners. Sports Med Open 2020; 6:16. [PMID: 32198675 PMCID: PMC7083975 DOI: 10.1186/s40798-020-00243-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 10/08/2019] [Accepted: 02/19/2020] [Indexed: 01/10/2023]
Abstract
Background Replication studies are essential for identifying credible associations between alleles and phenotypes. Validation of genotype-phenotype associations in the sports and exercise field is rare. An initial genetic association study suggested that rs1049305 (C > G) in the 3′ untranslated region (3′UTR) of the aquaporin-1 (AQP1) gene was associated with marathon running (MR) performance level in Hispanic males. To validate this finding, we conducted a replication analysis in an independent case-control sample of Hispanic male marathon runners (n = 1430; cases n = 713 and controls n = 717). A meta-analysis was utilized to test the extent of the association between the initial results and the present report. It also provided to test the heterogeneity (variation) between the two studies. Results The replication study showed a statistically significant (p ≤ 0.05) association between rs1049305 (C > G) of the AQP1 gene and MR performance level. Association test results using a fixed effect model for the combined, original study and the present report, yielded an odds ratio = 1.28, 95% confidence interval = 1.13–1.45, p = 0.0001. The extent of the measures of heterogeneity was Tau-squared = 0, H statistic = 1, I2 statistic = 0, and Cochran’s Q test (Q = 0.29; p value 0.59), indicated the variation between studies were due to chance and not to differences in heterogeneity between the two studies. Within the limitations of the present replication, contrast of two studies and its effects on meta-analysis, the findings were robust. Conclusion This study successfully replicated the results of Martínez et al. (Med Sportiva 13:251-5, 2009). The meta-analysis provided further epidemiological credibility for the hypothesis of association between the DNA rs1049305 (C > G) variation in the 3′UTR of the AQP1 gene and MR running performance level in Hispanics male marathon runners. It is not precluded that a linked DNA structure in the surrounding molecular neighborhood could be of influence by been part of the overly complex phenotype of MR performance level.
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Affiliation(s)
- Miguel A Rivera
- Department of Physical Medicine, Rehabilitation & Sports Medicine, School of Medicine, University of Puerto Rico, Main Building Office A204, San Juan, PR, 00936, USA.
| | - Thomas D Fahey
- Department of Kinesiology, California State University, Chico, CA, USA
| | - Juan R López-Taylor
- Physical Activity and Applied Sport Sciences Institute, Universidad de Guadalajara, Guadalajara, Jalisco, México
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Flecha-Velazquez K, Fahey TD, Martínez JL, Lopez-Taylor JR, Rivera MA. KCNA4 Gene Variant is Auxiliary in Endurance Running Performance Level. Int J Sports Med 2019; 40:354-358. [PMID: 30812034 DOI: 10.1055/a-0824-5394] [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: 10/27/2022]
Abstract
The present is an observational study following a genetic epidemiology model using a case-control design. We tested the hypothesis of an association between the prevalence of the genotypic and allelic frequencies distribution of the potassium voltage-gated channel of the shaker related subfamily member 4 gene (KCNA4) rs1323860 (C/T transition) and endurance performance level in Hispanic male marathon runners (MR). The subjects (n=1876) were adult Hispanic male MR. Fast-MR (cases; n=938) were finishers in the top 3rd percentile. Slow MR (controls; n=938) were finishers in the lowest 3rd percentile of their respective age. Genomic DNA was purified from a whole blood sample. Polymerase chain reaction was used to amplify a KCNA4 SNP which consists of a C/T (rs1323860) transition. The observed genotype frequencies, in both Cases and Controls, met Hardy-Weinberg equilibrium (X2, P≥0.05). Genotype and allele frequencies were statistically different (P<0.01) between cases and controls. Odds ratio revealed that the C allele was 1.33 times more likely prevalent in the cases than in the controls (95% CI; 1.17, 1.51; P<0.001). The magnitude of the statistical power for the present study was 0.86. In conclusion, the findings strongly suggest that KCNA4 gene rs1323860 (C/T transition) is auxiliary in the complex phenotype of endurance running performance level in Hispanic male marathon runners.
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Affiliation(s)
- Keven Flecha-Velazquez
- Department Physical Medicine, Rehabilitation & Sports Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Thomas D Fahey
- Department Kinesiology, California State University - Chico, Chico, United States
| | - Juan L Martínez
- Sinaloense Sports Institute, Sport Medicine and Applied Sciences Unit, Culiacan, Mexico
| | - Juan R Lopez-Taylor
- Universidad de Guadalajara, Physical Activity and Applied Sport Sciences Institute, Guadalajara, Mexico
| | - Miguel A Rivera
- Department Physical Medicine, Rehabilitation & Sports Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
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Mazarío-Fernández A, Torres-Pardo A, Varela A, Parras M, Martínez JL, Fernández-Díaz MT, Hernando M, González-Calbet JM. Atomically Resolved Short-Range Order at the Nanoscale in the Ca-Mn-O System. Inorg Chem 2017; 56:11753-11761. [PMID: 28898062 DOI: 10.1021/acs.inorgchem.7b01728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The elucidation of the reaction mechanisms involving redox processes in functional transition-metal oxides, which usually start in areas of very few nanometers in size, is yet a challenge to be satisfactorily achieved. Atomically resolved HAADF and EELS have provided both chemical and structural information at the nanoscale, which reveal the preservation of short-range cationic order in areas of 2-3 nm length as the driving force behind the reversibility of the Ca2Mn3O8-Ca2Mn3O5 redox process. Oxygen evolution is accommodated by cationic diffusion along the Ca and Mn layers of the cation-deficient Ca2Mn3O8 delafossite related structure, whereas Mn remains octahedrally coordinated.
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Affiliation(s)
- A Mazarío-Fernández
- ICTS-Centro Nacional de Microscopía Electrónica, Universidad Complutense , 28040 Madrid, Spain
| | - A Torres-Pardo
- Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense , 28040 Madrid, Spain
| | - A Varela
- Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense , 28040 Madrid, Spain
| | - M Parras
- Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense , 28040 Madrid, Spain
| | - J L Martínez
- ESS Bilbao , Pol. Ugaldeguren III, Pol. A-7B, 48170 Zamudio. Spain
| | - M T Fernández-Díaz
- Institute Laue Langevin , 71 avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France
| | - M Hernando
- Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense , 28040 Madrid, Spain
| | - J M González-Calbet
- ICTS-Centro Nacional de Microscopía Electrónica, Universidad Complutense , 28040 Madrid, Spain.,Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense , 28040 Madrid, Spain
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Gharsallah M, Serrano-Sánchez F, Bermúdez J, Nemes NM, Martínez JL, Elhalouani F, Alonso JA. Nanostructured Bi2Te3 Prepared by a Straightforward Arc-Melting Method. Nanoscale Res Lett 2016; 11:142. [PMID: 26976428 PMCID: PMC4791409 DOI: 10.1186/s11671-016-1345-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 02/27/2016] [Indexed: 06/04/2023]
Abstract
Thermoelectric materials constitute an alternative source of sustainable energy, harvested from waste heat. Bi2Te3 is the most utilized thermoelectric alloy. We show that it can be readily prepared in nanostructured form by arc-melting synthesis, yielding mechanically robust pellets of highly oriented polycrystals. This material has been characterized by neutron powder diffraction (NPD), scanning electron microscopy (SEM), and electronic and thermal transport measurements. A microscopic analysis from NPD data demonstrates a near-perfect stoichiometry of Bi2Te3 and a fair amount of anharmonicity of the chemical bonds. The as-grown material presents a metallic behavior, showing a record-low resistivity at 320 K of 2 μΩ m, which is advantageous for its performance as a thermoelectric material. SEM analysis shows a stacking of nanosized sheets, each of them presumably single-crystalline, with large surfaces perpendicular to the c crystallographic axis. This nanostructuration notably affects the thermoelectric properties, involving many surface boundaries that are responsible for large phonon scattering factors, yielding a thermal conductivity as low as 1.2 W m(-1) K(-1) around room temperature.
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Affiliation(s)
- M Gharsallah
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain
- National School of Engineers, Sfax University, Sfax, B. P. W 3038, Tunisia
| | - F Serrano-Sánchez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain
| | - J Bermúdez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain
| | - N M Nemes
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain
| | - J L Martínez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain
| | - F Elhalouani
- National School of Engineers, Sfax University, Sfax, B. P. W 3038, Tunisia
| | - J A Alonso
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049, Madrid, Spain.
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7
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Gharsallah M, Serrano-Sánchez F, Nemes NM, Mompeán FJ, Martínez JL, Fernández-Díaz MT, Elhalouani F, Alonso JA. Giant Seebeck effect in Ge-doped SnSe. Sci Rep 2016; 6:26774. [PMID: 27251233 PMCID: PMC4890000 DOI: 10.1038/srep26774] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 05/06/2016] [Indexed: 11/09/2022] Open
Abstract
Thermoelectric materials may contribute in the near future as new alternative sources of sustainable energy. Unprecedented thermoelectric properties in p-type SnSe single crystals have been recently reported, accompanied by extremely low thermal conductivity in polycrystalline samples. In order to enhance thermoelectric efficiency through proper tuning of this material we report a full structural characterization and evaluation of the thermoelectric properties of novel Ge-doped SnSe prepared by a straightforward arc-melting method, which yields nanostructured polycrystalline samples. Ge does not dope the system in the sense of donating carriers, yet the electrical properties show a semiconductor behavior with resistivity values higher than that of the parent compound, as a consequence of nanostructuration, whereas the Seebeck coefficient is higher and thermal conductivity lower, favorable to a better ZT figure of merit.
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Affiliation(s)
- M Gharsallah
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain.,Sfax University, National School of Engineers, B. P. W 3038, Tunisia
| | - F Serrano-Sánchez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
| | - N M Nemes
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
| | - F J Mompeán
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
| | - J L Martínez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
| | | | - F Elhalouani
- Sfax University, National School of Engineers, B. P. W 3038, Tunisia
| | - J A Alonso
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
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Abstract
Heme biosynthesis is a highly conserved pathway which is present in all kingdoms, from Archaea to higher organisms such as plants and mammals. The heme molecule acts as a prosthetic group for different proteins and enzymes involved in energy metabolism and reactions involved in electron transfer. Based on our recent findings and other recent reports, we here illustrate that heme is more than a co-factor. We also discuss the necessity to gain more insight into the heme biosynthesis pathway regulation, as this interacts closely with overall stress control. Understanding heme biosynthesis and its regulation could impact our ability to develop more efficient yeast cell factories for heterologous protein production.
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Affiliation(s)
- J L Martínez
- a Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology , Gothenburg , Sweden.,b Department of Biology and Biological Engineering , Chalmers University of Technology , Göteborg , Sweden
| | - D Petranovic
- a Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology , Gothenburg , Sweden.,b Department of Biology and Biological Engineering , Chalmers University of Technology , Göteborg , Sweden
| | - J Nielsen
- a Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology , Gothenburg , Sweden.,b Department of Biology and Biological Engineering , Chalmers University of Technology , Göteborg , Sweden.,c Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark , Hørsholm , Denmark
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García-León G, Ruiz de Alegría Puig C, García de la Fuente C, Martínez-Martínez L, Martínez JL, Sánchez MB. High-level quinolone resistance is associated with the overexpression of smeVWX in Stenotrophomonas maltophilia clinical isolates. Clin Microbiol Infect 2015; 21:464-7. [PMID: 25753190 DOI: 10.1016/j.cmi.2015.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 01/31/2023]
Abstract
Stenotrophomonas maltophilia is the only known bacterium in which quinolone-resistant isolates do not present mutations in the genes encoding bacterial topoisomerases. The expression of the intrinsic quinolone resistance elements smeDEF, smeVWX and Smqnr was analysed in 31 clinical S. maltophilia isolates presenting a minimum inhibitory concentration (MIC) range to ciprofloxacin between 0.5 and > 32 μg/mL; 11 (35.5%) overexpressed smeDEF, 2 (6.5%) presenting the highest quinolone MICs overexpressed smeVWX and 1 (3.2%) overexpressed Smqnr. Both strains overexpressing smeVWX presented changes at the Gly266 position of SmeRv, the repressor of smeVWX. Changes at the same position were previously observed in in vitro selected S. maltophilia quinolone-resistant mutants, indicating this amino acid is highly relevant for the activity of SmeRv in repressing smeVWX expression. For the first time SmeVWX overexpression is associated with quinolone resistance of S. maltophilia clinical isolates.
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Affiliation(s)
- G García-León
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, Madrid, Spain
| | - C Ruiz de Alegría Puig
- Service of Microbiology, Hospital Universitario Marqués de Valdecilla-IDIVAL, Avda. Valdecilla s/n, Santander, Spain
| | - C García de la Fuente
- Service of Microbiology, Hospital Universitario Marqués de Valdecilla-IDIVAL, Avda. Valdecilla s/n, Santander, Spain
| | - L Martínez-Martínez
- Service of Microbiology, Hospital Universitario Marqués de Valdecilla-IDIVAL, Avda. Valdecilla s/n, Santander, Spain; Department of Molecular Biology, University of Cantabria, Cardenal Herrera Oria, s/n, Santander, Spain
| | - J L Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, Madrid, Spain.
| | - M B Sánchez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, Madrid, Spain.
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Cortés-Gil R, Ruiz-González ML, Alonso JM, Martínez JL, Hernando A, Vallet-Regí M, González-Calbet JM. Surprising resistivity decrease in manganites with constant electronic density. J Phys Condens Matter 2013; 25:484002. [PMID: 24200948 DOI: 10.1088/0953-8984/25/48/484002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A decrease of eight orders of magnitude in the resistance of (La0.5Ca0.5)zMnO3 has been detected when the electronic density is kept constant while the calcium content is modified by introducing cationic vacancies. This effect is related to the disappearance of the charge ordering state and the emergence of an antiferromagnetic–ferromagnetic transition. Moreover, high values of the colossal magnetoresistance above room temperature are attained.
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Hussain A, Martínez JL, Lizana A, Campos J. Super resolution imaging achieved by using on-axis interferometry based on a Spatial Light Modulator. Opt Express 2013; 21:9615-9623. [PMID: 23609671 DOI: 10.1364/oe.21.009615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An interferometry based method to achieve resolution beyond the diffraction barrier is proposed. Object is illuminated with different tilted beams, generated by using a Spatial Light Modulator (SLM). In addition, some constant phases are also assigned to each tilted beam with the SLM display. Then, the object is simultaneously illuminated with all tilted beams, producing an on-axis interferometry scheme. An interferogram at the image plane is formed for each set of constant phases added to the tilted beams. Using proper selection of constant phases for each of the interferograms, the synthetic aperture can be calculated. During the post processing, we take the Fourier transforms of the each image and the portions of the spectrum are spatially shifted and combined to obtain synthesized spectrum whose inverse Fourier transform gives high resolution image.
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Affiliation(s)
- Anwar Hussain
- Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Nilore 45650, Islamabad, Pakistan
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12
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García-Martínez P, Martínez JL, Sánchez-López MM, Moreno I. Wavelength-compensated time-sequential multiplexed color joint transform correlator. Appl Opt 2010; 49:4866-4873. [PMID: 20830174 DOI: 10.1364/ao.49.004866] [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] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report a wavelength-compensated three-channel (RGB) joint transform correlator (JTC) for color pattern recognition using a ferroelectric liquid-crystal spatial light modulator (SLM) operating in binary pure phase modulation. We apply a previously reported time-multiplexing technique useful in creating wavelength-compensated diffraction patterns, based on the synchronization of properly scaled diffraction masks with the input wavelength selection obtained by applying a rotating RGB color-filter wheel to an Ar-Kr laser. The application of this technique to a JTC architecture permits real-time color object detection. In order to achieve a high light efficiency for the correlation process, we combine the design of zero-order joint power spectra in all color channels with the selection of a certain polarization configuration of the SLM, producing a broadband phase-only modulation. Excellent experimental results demonstrating color-object detection are provided.
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Affiliation(s)
- P García-Martínez
- Departamento de Optica, Universitat de València, C/Doctor Moliner 50, 46100 Burjassot, Spain.
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Llop E, de la Revilla J, Pons F, Peñas B, Martínez JL, Abreu L, Calleja JL. Decrease in viral load at weeks 12 and 24 in patients with chronic hepatitis B treated with lamivudine or adefovir predicts virological response at week 48. Rev Esp Enferm Dig 2010; 101:763-7. [PMID: 20001153 DOI: 10.4321/s1130-01082009001100003] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIM The aim of our study was to evaluate the decrease in viral load (VL) that is able to predict antiviral treatment response at one year in patients with chronic hepatitis B. METHODS The clinical records of 66 patients, 31 treated with lamivudine (LAM) and 35 treated with adefovir (ADF), were retrospectively reviewed. We measured viral DNA at months 1, 3 and 6. RESULTS The LAM group showed virological response (VR) in 51.6% of patients. Baseline VL was higher in non responders (5.37 +/- 1.16 vs. 7.01 +/- 1.05; p < 0.001). Responders showed a higher percentage of VL decrease at month 3 from baseline (49.2 vs. 38.3%; p = 0.03). We designed a ROC curve and established a cutoff point for decrease of 30% that had 80% of negative predictive value (NPV).The ADF group showed VR in 57.1% of patients. Baseline VL was higher in nonresponders (4.67 +/- 1.22 vs. 5.78 +/- 1.34; p = 0.01). We observed a significant decrease in VL (log) at months 3 (2.6 +/- 1.1 vs. 1.3 +/- 1.3; p = 0.03) and 6 (2.6 +/- 1.2 vs. 1.3 +/- 1.2; p = 0.006). The percentage of decrease of VL from baseline was also statistically significant. We created ROC curves at months 3 and 6, and established the best cutoff points. At month 6 a decrease of 1 log in VL had a NPV of 80%, and a decrease of 20% in VL from baseline had 100% NPV. CONCLUSION The decrease in viral DNA at weeks 12 and 24 can predict VR at one year in patients with chronic hepatitis B treated with LAM or ADF. This could optimize treatment.
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Affiliation(s)
- E Llop
- Service of Gastroenterology and Hepatology, University Hospital Puerta de Hierro, Madrid, Spain
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14
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Abstract
Antibiotics are likely the most important compounds used for human therapy. Conversely, antibiotic resistance is a relevant medical problem. However, besides their relevance for human health, antibiotics and their resistance genes are important elements that can influence the structure of microbial populations. In this article, we discuss antibiotics and antibiotic resistance genes in non-clinical environments.
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Affiliation(s)
- A Fajardo
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CSIC), Cantoblanco, Madrid, Spain
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15
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Suderow H, Tissen VG, Brison JP, Martínez JL, Vieira S. Pressure induced effects on the Fermi surface of superconducting 2H-NbSe2. Phys Rev Lett 2005; 95:117006. [PMID: 16197038 DOI: 10.1103/physrevlett.95.117006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Indexed: 05/04/2023]
Abstract
The pressure dependence of the critical temperature T(c) and upper critical field H(c2)(T) has been measured up to 19 GPa in the layered superconducting material 2H-NbSe2. T(c)(P) has a maximum at 10.5 GPa, well above the pressure for the suppression of the charge density wave (CDW) order. Using an effective two-band model to fit H(c2)(T), we obtain the pressure dependence of the anisotropy in the electron-phonon coupling and Fermi velocities, which reveals the peculiar interplay between CDW order, Fermi surface complexity, and superconductivity in this system.
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Affiliation(s)
- H Suderow
- Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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16
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Pinacca R, Viola MC, Pedregosa JC, Muñoz A, Alonso JA, Martínez JL, Carbonio RE. Crystal and magnetic structure of the double perovskite Sr2CoUO6: a neutron diffraction study. Dalton Trans 2005:447-51. [PMID: 15672187 DOI: 10.1039/b415915b] [Citation(s) in RCA: 19] [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: 11/21/2022]
Abstract
Sr2CoUO6 double perovskite has been prepared as a polycrystalline powder by solid-state reaction, in air. This material has been studied by X-ray, neutron powder diffraction (NPD) and magnetic measurements. At room temperature, the crystal structure is monoclinic, space group P2(1)/n, Z= 2, with a= 5.7916(2), b= 5.8034(2), c= 8.1790(3) A, beta= 90.1455(6)degrees. The perovskite lattice consists of a completely ordered array of CoO6 and UO6 octahedra, which exhibit an average tilting angle phi= 11.4 degrees. Magnetic and neutron diffraction measurements indicate an antiferromagnetic ordering below TN = 10 K. The low-temperature magnetic structure was determined by NPD, selected among the possible magnetic solutions compatible with the P2(1)/n space group, according with the group theory representation. The propagation vector is k= 0. A canted antiferromagnetic structure is observed below TN = 10 K, which remains stable down to 3 K, with an ordered magnetic moment of 2.44(7)mu(B) for Co2+ cations. The magnetic moment calculated from the Curie-Weiss law at high temperatures (5.22 mu(B)/f.u.) indicates that the orbital contribution is unquenched at high temperatures, which is consistent with high-spin Co2+((4)T(1g) ground state) in a quasi-regular octahedral environment. Magnetic and structural features are consistent with an electronic configuration Co2+[3d(7)]-U6+[Rn].
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Affiliation(s)
- R Pinacca
- Area de Química General e Inorgánica Dr. Gabino F. Puelles, Departamento de Química, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700, San Luis, Argentina
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17
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Gutiérrez J, Carlos S, Martínez JL, Liébana JL, Soto MJ, Luna JDD, Piédrola G. [A study of clinical response to antibiotic treatment in subjects with chronic bacterial prostatitis]. Rev Esp Quimioter 2004; 17:189-92. [PMID: 15470514] [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] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
A study was carried out on the clinical response to antibiotics in 105 patients with chronic bacterial prostatitis. Two groups of patients were compared in a retrospective study. The results of rectal examination, ultrasound scan, microbiological analysis, and response to different antibiotic therapy regimens were compared. There was a high incidence of perineal-testicular pain and sexual potency reduction; prostate congestion and pain on rectal examination were frequently reported. All the patients had positive microbial cultures, with Gram-negative microorganisms being predominantly isolated. Following the administration of different antibiotic therapy regimens, symptoms either disappeared or diminished, irrespective of whether positive cultures remained. A poorer clinical response was observed in patients with positive prostate ultrasound and rectal examination, and with isolated Gram-negative bacilli. No differences were observed between either group in clinical response to different antimicrobial regimens.
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Affiliation(s)
- J Gutiérrez
- Departamento de Microbiología, Hospital Universitario San Cecilio, Universidad de Granada, Granada.
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18
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García-Hernández M, Martínez JL, Martínez-Lope MJ, Casais MT, Alonso JA. Finding universal correlations between cationic disorder and low field magnetoresistance in FeMo double perovskite series. Phys Rev Lett 2001; 86:2443-2446. [PMID: 11289950 DOI: 10.1103/physrevlett.86.2443] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2000] [Revised: 12/28/2000] [Indexed: 05/23/2023]
Abstract
We search for general patterns that explain the low field magnetoresistance at low temperatures in the system A(2-x)A'xFeMoO6. The observed linear dependence of the low field magnetoresistance with the saturation magnetization for the series is related to the antisite disorder at the Fe and Mo sites. This is explained in terms of a spin dependent crossing of intragranular barriers originated from the presence of antiferromagnetic SrFeO3 patches that naturally develop when antisite disorder occurs in the double perovskite. The presence of a moderate level of antisite disorder is at the very root of low field magnetoresistance although effects such as disorder distribution, connectivity, or morphology add their contribution.
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Affiliation(s)
- M García-Hernández
- Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, E-28049 Madrid, Spain
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19
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Calleja JL, Albillos A, Rossi I, Moreno R, Domper F, Martínez JL, Escartín P. Time course of serum hepatitis C virus-RNA during chronic hepatitis C treatment accurately predicts the type of response. Aliment Pharmacol Ther 2001; 15:241-9. [PMID: 11148444 DOI: 10.1046/j.1365-2036.2001.00921.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
AIM To establish the value of alanine aminotransferase normalization and hepatitis C virus-RNA clearance as predictors of sustained virological response in naïve and relapser chronic hepatitis C patients on mono or combination therapy. METHODS A total of 282 hepatitis C patients were studied: 98 naïves on interferon, and 64 naïves and 75 relapsers on interferon plus oral ribavirin; 45 patients were excluded. Drugs were administered at standard doses for 12 months. Alanine aminotransferase and hepatitis C virus-RNA were determined at baseline and at weeks 4, 12, 24, 48, and at 72 and 96 weeks after completion of therapy. RESULTS The rate of sustained response was greater (P < 0.05) in naïves and relapsers on combination therapy (33% and 48%, respectively) than in naïves on interferon alone (16%). Hepatitis C virus-RNA significantly decreased from baseline by week 4 in naïves on interferon and relapsers on combination therapy and by week 12 in naïves on combination therapy. Alanine aminotransferase levels paralleled viremic load in naïves on interferon, yet in patients on combination therapy, alanine aminotransferase normalized independently of the virological response. During treatment, the main factor associated with sustained response was hepatitis C virus-RNA clearance by week 4 in naïves on interferon and relapsers on combination therapy, and by week 24 in naïves on combination therapy. CONCLUSION Clearance of viraemia constitutes the best predictor of a sustained response to therapy, but needs to be measured at patient-specific times.
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Affiliation(s)
- J L Calleja
- Department of Gastroenterology, Clinica Puerta de Hierro, University Autonoma, Madrid, Spain
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20
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Martínez MA, Moreno A, Aguirre de Cárcer A, Cabrera R, Rocha R, Torre A, Nevado A, Ramos T, Neri J, Antón G, Miranda I, Fernández P, Rodríguez E, Miquel A, Martínez JL, Rodríguez M, Eisman C, Puig JG. Frequency and determinants of microalbuminuria in mild hypertension: a primary-care-based study. J Hypertens 2001; 19:319-26. [PMID: 11212976 DOI: 10.1097/00004872-200102000-00020] [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: 11/25/2022]
Abstract
OBJECTIVE To evaluate the frequency of microalbuminuria and its relationship with several risk factors and left ventricular mass in a population of mildly hypertensive subjects attended in a primary-care setting. DESIGN Cross-sectional study. SETTING Eight primary-care centres. PATIENTS Two hundred and twenty-three non-diabetic patients recently diagnosed with mild hypertension were included in the study. None of them had clinical evidence of target-organ damage or had received prior antihypertensive treatment. INTERVENTIONS Subjects included in the study underwent clinical interview, measurement of blood pressure (BP) on three visits, blood analysis, measurement of albumin by immunonephelometry in three overnight urine collections, 24 h BP monitoring and M-mode and Doppler echocardiography. MAIN OUTCOME MEASURES Tobacco habit, clinic BP, body mass index, serum lipids and uric acid, glycaemia, urinary albumin excretion (UAE), ambulatory BP and left ventricular mass index. RESULTS The frequency of microalbuminuria was 7.2%. Microalbuminuric patients were more likely to be men and to be characterized by higher ambulatory BP, body mass index and uric acid levels. Regression analysis demonstrated that male sex and 24 h systolic BP were determinants of UAE. Patients with white-coat hypertension showed lower UAE than did subjects with sustained hypertension. Although a certain relationship between UAE and left ventricular mass index was found, these variables were not significantly correlated. CONCLUSIONS A low proportion of mildly hypertensive patients attended in a primary care setting are microalbuminuric. In this population, UAE is an expression of BP values over 24 h and correlates with several risk factors.
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Affiliation(s)
- M A Martínez
- Hospital and Primary Care Research Unit, Hospital La Paz, Universidad Autónoma de Madrid, Spain.
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21
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Affiliation(s)
- A Alonso
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotechnología, CSIC, Cantoblanco, Madrid, Spain
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22
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Morosini MI, Ayala JA, Baquero F, Martínez JL, Blázquez J. Biological cost of AmpC production for Salmonella enterica serotype Typhimurium. Antimicrob Agents Chemother 2000; 44:3137-43. [PMID: 11036037 PMCID: PMC101617 DOI: 10.1128/aac.44.11.3137-3143.2000] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [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: 11/20/2022] Open
Abstract
Chromosomally mediated AmpC-type beta-lactamases are frequently found among Enterobacteriaceae. Hyperproduction of AmpC beta-lactamase results in high-level resistance to beta-lactam antibiotics. One striking feature of Salmonella is the absence of the structural ampC gene, encoding AmpC beta-lactamase, in contrast with other members in the Enterobacteriaceae family, such as Escherichia, Citrobacter, or Enterobacter. The horizontal acquisition of ampC genes is one of the causes of the increased resistance to extended-spectrum cephalosporins and beta-lactamase inhibitors among gram-negative rods. Nevertheless, despite the high number of beta-lactam-resistant Salmonella isolates so far described, only two strains expressing resistance to cephalosporin and beta-lactamase inhibitors which is mediated by AmpC-type enzymes have been found. In this work, data are provided which support the possibility that the maintenance and expression of the ampC gene may represent an unbearable cost for Salmonella in terms of reduction of some of its lifestyle attributes, such as growth rate and invasiveness. The deleterious AmpC burden can be eliminated by decreasing the production of AmpC when both the regulatory gene, ampR, and ampC are present in Salmonella. Thus, it is suggested that the two genes have to be acquired together by Salmonella, leading to an inducible beta-lactam resistance phenotype. AmpC synthesis did not produce major variations in the peptidoglycan composition of Salmonella.
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Affiliation(s)
- M I Morosini
- Servicio de Microbiología, Hospital Ramón y Cajal, Madrid, Spain
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23
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Abstract
Stenotrophomonas maltophilia is a nosocomial bacterial pathogen intrinsically resistant to several antibiotics. The mechanisms involved in this intrinsic multiresistance phenotype are poorly understood. A library of chromosomal DNA from a spontaneous multidrug-resistant S. maltophilia D457R mutant (A. Alonso and J. L. Martinez, Antimicrob. Agents Chemother. 41:1140-1142, 1997) was screened for complementation of erythromycin susceptibility on an antibiotic-hypersusceptible Escherichia coli DeltaacrAB strain. Cloning and further analysis revealed that a 6-kbp region constituting a transcriptional unit was capable of complementing the antibiotic-susceptible phenotype of an E. coli DeltaacrAB strain. We identified three open reading frames, smeD, smeE and smeF, which code for members of the membrane fusion protein, resistance nodulation division, and outer membrane factor families, respectively. Drug susceptibility assays indicated that the SmeDEF system cloned in E. coli mediates resistance to a wide range of antibiotics. Ethidium bromide and norfloxacin accumulation experiments in the presence and in the absence of carbonyl cyanide m-chlorophenylhydrazone showed that this system constitutes a drug efflux pump dependent on the membrane proton motive force. The presence of high levels of smeDEF mRNA in the multiresistant D457R mutant was consistent with the high levels of SmeF (formerly Omp54) observed in the same strain. In contrast, transcription levels of smeDEF in the D457 strain were tiny, which correlates with the low levels of SmeF observed for this strain. Also, for both the D457 and D457R strains, we observed growth phase-dependent regulation in which the highest level of transcription corresponded to early exponential phase, with transcription decreasing throughout the growth curve to undetectable levels at 24 h.
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Affiliation(s)
- A Alonso
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Campus Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain
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24
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Ramos ML, Palacios JJ, Fournier BG, Martínez JL, Martinez-López J, Conde MC, Izquierdo AM, García MM, Miranda EB. Prognostic value of tumoral ploidy in a series of spanish patients with acute lymphoblastic leukemia. Cancer Genet Cytogenet 2000; 122:124-30. [PMID: 11106823 DOI: 10.1016/s0165-4608(00)00290-9] [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] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The prognostic value of tumoral ploidy and its relation with nonrandom chromosome alterations were analyzed in 89 cases of acute lymphoblastic leukemia. Ploidy is associated with the number of nonrandom chromosome alterations and survival. The pseudodiploid and hypodiploid groups had a high incidence of nonrandom alterations and poor survival while the diploid and high hyperdiploid groups had a lower incidence of nonrandom alterations and longer survivals. The patients in the low hyperdiploid group with random alterations received the same treatment as the diploid and high hyperdiploid groups but had poor survivals. Our analysis confirms that ploidy is a very important prognostic factor and suggests that patients with low hyperdiploidy should receive intensive therapies similar to those of patients in the groups with a high number of nonrandom alterations.
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Affiliation(s)
- M L Ramos
- Servicio de Genética, Hospital 12 de Octubre (edificio Materno-Infantil), Carretera de Andalucía Km 5.400, 28041, Madrid, Spain.
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25
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Alonso A, Sanchez P, Martínez JL. Stenotrophomonas maltophilia D457R contains a cluster of genes from gram-positive bacteria involved in antibiotic and heavy metal resistance. Antimicrob Agents Chemother 2000; 44:1778-82. [PMID: 10858330 PMCID: PMC89961 DOI: 10.1128/aac.44.7.1778-1782.2000] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [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: 01/01/2023] Open
Abstract
A cluster of genes involved in antibiotic and heavy metal resistance has been characterized from a clinical isolate of the gram-negative bacterium Stenotrophomonas maltophilia. These genes include a macrolide phosphotransferase (mphBM) and a cadmium efflux determinant (cadA), together with the gene cadC coding for its transcriptional regulator. The cadC cadA region is flanked by a truncated IS257 sequence and a region coding for a bin3 invertase. Despite their presence in a gram-negative bacterium, these genetic elements share a common gram-positive origin. The possible origin of these determinants as a remnant composite transposon as well as the role of gene transfer between gram-positive and gram-negative bacteria for the acquisition of antibiotic resistance determinants in chronic, mixed infections is discussed.
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Affiliation(s)
- A Alonso
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Campus UAM, Cantoblanco, 28049-Madrid, Spain
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26
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Pérez-Urizar J, Granados-Soto V, Castañeda-Hernández G, Hong E, González C, Martínez JL, Flores-Murrieta FJ. Analgesic efficacy and bioavailability of ketorolac in postoperative pain: a probability analysis. Arch Med Res 2000; 31:191-6. [PMID: 10880726 DOI: 10.1016/s0188-4409(00)00050-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 11/18/2022]
Abstract
BACKGROUND The analgesic efficacy and bioavailability of 30 mg intramuscular ketorolac was studied in 24 patients with severe or very severe postoperative pain. METHODS Pain and pain relief were determined by a five-point verbal rating scale and data were submitted to a probability analysis. Ketorolac plasma levels were determined by high-performance liquid chromatography. RESULTS Two patients chose not to finish the study; 22 patients completed the study achieving at least good pain relief. Of these 22 patients, 13 reached complete pain relief. Ketorolac was rapidly absorbed. Notwithstanding, pain relief increased gradually, showing considerable delay with regard to plasma concentrations. Analysis of the probability-time curves revealed that 25% of the patients obtained moderate pain relief at 7 min after ketorolac administration, 50% at 11 min, 75% at 29 min, and 95% at 60 min. Good pain relief was achieved in 25, 50, and 75% of the patients at 1.1, 1.8, and 2.7 h, respectively. Complete pain relief was achieved in 25% and 50% of the patients at 2.6 h and 3.7 h, respectively. The probability of exhibiting an acceptable pain relief in responsive patients for more than 5 h was 0.97. No serious side effects were detected. CONCLUSIONS Results show that 30 mg intramuscular ketorolac is an adequate treatment for postoperative pain in the Mexican population. Therefore, the use of higher doses is not justified. Due to gradual installation of analgesia, administration of additional analgesic medication before 1 h is not recommended.
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MESH Headings
- Adult
- Analgesics, Non-Narcotic/administration & dosage
- Analgesics, Non-Narcotic/blood
- Analgesics, Non-Narcotic/pharmacokinetics
- Analgesics, Non-Narcotic/therapeutic use
- Anti-Inflammatory Agents, Non-Steroidal/administration & dosage
- Anti-Inflammatory Agents, Non-Steroidal/blood
- Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics
- Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
- Biological Availability
- Chromatography, High Pressure Liquid
- Elective Surgical Procedures
- Female
- Humans
- Injections, Intramuscular
- Ketorolac/administration & dosage
- Ketorolac/blood
- Ketorolac/pharmacokinetics
- Ketorolac/therapeutic use
- Male
- Middle Aged
- Pain, Postoperative/blood
- Pain, Postoperative/drug therapy
- Treatment Outcome
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Affiliation(s)
- J Pérez-Urizar
- Departamento de Farmacología y Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV del IPN), México, D.F., Mexico.
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27
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Alonso A, Campanario E, Martínez JL. Emergence of multidrug-resistant mutants is increased under antibiotic selective pressure in Pseudomonas aeruginosa. Microbiology (Reading) 1999; 145 ( Pt 10):2857-62. [PMID: 10537207 DOI: 10.1099/00221287-145-10-2857] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pseudomonas aeruginosa is one of the most important opportunistic pathogens involved in nosocomial infections, cystic fibrosis patients included. Hospital isolates frequently present multidrug-resistance (MDR) phenotypes as the consequence of constant antibiotic selective pressure. The kinetics of emergence of P. aeruginosa MDR mutants under antibiotic selective pressure indicated that long-term incubation in the presence of the bacteriostatic antibiotic tetracycline increases the mutation rate per cell per day of P. aeruginosa PAO1 by several orders of magnitude. The tetracycline-resistant mutants obtained were stable, showed decreased susceptibility to antibiotics belonging to different structural families, and contained an outer-membrane protein not present in the wild-type P. aeruginosa strain PAO1. These data are consistent with the hypothesis that incubation in the presence of tetracycline favours the emergence of MDR mutants in P. aeruginosa. The results are relevant for understanding the rapid emergence of antibiotic-resistant mutants among bacterial populations during infections. Their relationship to other models of increased mutagenesis under stress is discussed with respect to the adaptive mutation phenomenon.
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Affiliation(s)
- A Alonso
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CSIC), Cantoblanco, Madrid, Spain
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28
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Alonso A, Rojo F, Martínez JL. Environmental and clinical isolates of Pseudomonas aeruginosa show pathogenic and biodegradative properties irrespective of their origin. Environ Microbiol 1999; 1:421-30. [PMID: 11207762 DOI: 10.1046/j.1462-2920.1999.00052.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.6] [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: 11/20/2022]
Abstract
Virulence properties of pathogenic bacteria, as well as resistance to antibiotics, are thought to arise through a specialization process favoured by the strong selection pressure imposed in clinical treatments. Nevertheless, in the case of opportunistic pathogens, it is unclear whether strains can be classified into virulent and non-virulent isolates. Clones of the opportunistic pathogen Pseudomonas aeruginosa do not seem to be associated to a particular biovar or pathovar, which suggests that virulence characteristics in opportunistic pathogens may already be present in environmental (non-clinical) isolates. We have explored this possibility, studying environmental isolates (mainly from oil-contaminated soils) and clinical isolates (from bacteraemia and cystic fibrosis patients) of P. aeruginosa. All environmental strains were found to actively efflux quinolones, which are synthetic antibiotics not expected to be present in the environment. These strains contained multidrug resistance determinants, were capable of invading epithelial cells and presented genes from the quorum-sensing and type III secretion systems. Some of them expressed either haemolytic or proteolytic activities or both, characteristics considered to be typical of virulent strains. All the strains tested, of clinical or environmental origin, could use alkanes (oil hydrocarbons) as a carbon source. Our results suggest that clinical and non-clinical P. aeruginosa strains might be functionally equivalent in several traits relevant for their virulence or environmental properties. Selection of clinically relevant traits, such as antibiotic resistance or cellular invasiveness, in opportunistic pathogens present in soil ecosystems is discussed.
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Affiliation(s)
- A Alonso
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, Madrid, Spain
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29
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Martínez JL, Morán P, Pendas AM, Taggart JB, García-Vázquez E. Genetic characterization and chromosomal location of a single locus GT microsatellite from Atlantic salmon. Anim Genet 1999; 30:399-400. [PMID: 10582305 DOI: 10.1046/j.1365-2052.1999.00526-22.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- J L Martínez
- Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, Spain
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30
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Sánchez P, Alonso A, Martínez JL. [Inhibition of pump and permeability mechanisms]. Rev Esp Quimioter 1999; 12:116-9. [PMID: 10562671] [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] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The presence of multidrug efflux-pump systems in bacteria showing resistance to various drugs is increasingly reported in the literature. These systems are inducible by compounds such as salicylate and can thus be involved in situations of phenotypic resistance at the point of the infection which would otherwise be barely detectable under standard laboratory testing conditions. On the other hand, mutants which overproduce efflux-pumps and show increased levels of antibiotic resistance are easily selectable. It has been shown that inactivation of efflux-pump determinants produces an increased susceptibility to different antibiotics as well as prevents the emergence of mutants with a high-level antibiotic resistance to drugs such as quinolones. The search for efflux-pump inhibitors to be used in combination with other currently used antibiotics is therefore an important task for the renewal of the antibacterial therapeutic armamentarium. No efflux-pump inhibitors are commercially available as yet. However, several companies are in the process of working on their development. In this review, we discuss four possible targets that could be useful in the screening of inhibitors of efflux-pump systems in bacteria.
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Affiliation(s)
- P Sánchez
- Centro Nacional de Biotecnología (CSIC), Campus Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid
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31
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Culebras E, Martínez JL. Aminoglycoside resistance mediated by the bifunctional enzyme 6'-N-aminoglycoside acetyltransferase-2"-O-aminoglycoside phosphotransferase. Front Biosci 1999; 4:D1-8. [PMID: 9872730 DOI: 10.2741/culebras] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The expression of the bifunctional aminoglycoside inactivating enzyme 6'-N-aminoglycoside acetyltransferase-2"-O-aminoglycoside phosphotransferase is the most important mechanism of high-level aminoglycoside resistance in Staphylococcus and Enterococcus. The enzyme is unique because it presents two different aminoglycoside-modifying activities located in different regions of the molecule. The gene aac(6')-aph(2") which encodes the synthesis of the enzyme is present in Tn4100-like transposons which are inserted both in R plasmids and the chromosomes of aminoglycoside-resistant isolates. The genetic structure of aac(6')-aph(2")-containing isolates indicates that their origin is not clonal, but plasmid conjugation together with multiple insertion events are in the basis of the rapid spread of aminoglycoside resistance among Gram-positive bacteria. There is not any prevalent genetic linkage of aac(6')-aph(2") with other antibiotic-resistance determinant. However, most methicillin resistant Staphylococcus strains present also high-level aminoglycoside resistance as the consequence of constant antibiotic pressure. This situation could change in the next future with the reported reemergence of gentamicin-susceptible MRSA isolates. Recent data show that inhibitors of eukaryotic protein kinases inhibit as well the aminoglycoside phosphotransferase activity. This effect indicates a common structure for these two families of proteins and opens the possibility for a meaningful survey of inhibitors of 6'-N-aminoglycoside acetyltransferase-2"-O-aminoglycoside phosphotransferase useful in clinical practice.
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Affiliation(s)
- E Culebras
- Servicio de Microbiología, Hospital Clínico San Carlos, Plaza de Cristo Rey s/n, 28048-Madrid, Spain
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32
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Martínez JL. [Inhibition mechanisms of permeability and XXXXX]. Rev Esp Quimioter 1998; 11:363-4. [PMID: 10336316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- J L Martínez
- Centro Nacional de Biotecnología (CSIC), Campus UAM, Cantoblanco, Madrid
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33
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Martínez JL, Alonso A, Gómez-Gómez JM, Baquero F. Quinolone resistance by mutations in chromosomal gyrase genes. Just the tip of the iceberg? J Antimicrob Chemother 1998; 42:683-8. [PMID: 10052889 DOI: 10.1093/jac/42.6.683] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J L Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, Madrid, Spain.
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34
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Hernández A, Mellado RP, Martínez JL. Metal accumulation and vanadium-induced multidrug resistance by environmental isolates of Escherichia hermannii and Enterobacter cloacae. Appl Environ Microbiol 1998; 64:4317-20. [PMID: 9797283 PMCID: PMC106645 DOI: 10.1128/aem.64.11.4317-4320.1998] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [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: 11/20/2022] Open
Abstract
Contaminated soils from an oil refinery were screened for the presence of microorganisms capable of accumulating either nickel, vanadium, or both metals. Three strains of bacteria that belonged to the family Enterobacteriaceae were selected. Two of them were Escherichia hermannii strains, and outer membrane profile (OMP) analysis showed that they were similar to a strain of clinical origin; the other one was an Enterobacter cloacae strain that differed from clinical isolates. The selected bacteria accumulated both nickel and vanadium. Growth in the presence of vanadium induced multidrug resistance phenotypes in E. hermannii and E. cloacae. Incubation with this metal changed the OMP profile of E. hermannii but did not produce variations in the expression of the major OMPs of E. cloacae.
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Affiliation(s)
- A Hernández
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CSIC), Campus Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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35
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Hadad Meléndez P, Martínez JL, Millán Marcelo JC, Aguiar Cruz F. [Determination of glucose-6-phosphate dehydrogenase deficiency to prevent possible drug-induced hemolysis]. Rev Cubana Med Trop 1998; 43:205. [PMID: 9768192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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36
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Alvarez J, Urda T, Mancha I, Martínez JL, Gutiérrez J, Such M, Vivancos R, de Mora M, Castillo JL, González de Vega N, Malpartida F. [Angina caused by subclavian-coronary steal in patients revascularized with internal mammary artery]. Rev Esp Cardiol 1998; 51:772-5. [PMID: 9803807 DOI: 10.1016/s0300-8932(98)74824-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 11/21/2022]
Abstract
After coronary bypass surgery in the left internal mammary artery, occlusive atherosclerosis in the proximal subclavian artery can produce reverse flow in the mammary artery and myocardial ischemia (coronary-subclavian steal syndrome). This is a rare cause of recurrent myocardial ischemia. We present two patients with postoperative complete obstruction in the proximal subclavian artery and inverse flow in the mammary artery producing severe ischemia in the left anterior descending artery territory. Both patients were treated with subclavian-subclavian bypass, which in one patient was ineffective in producing an adequate anterograde flow in the left internal mammary artery. We review clinical management, diagnostic methods and therapeutic options used in the coronary-subclavian steal syndrome.
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Affiliation(s)
- J Alvarez
- Servicio de Cardiología, Hospital Regional Universitario Carlos Haya, Málaga
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37
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López-Dóriga MV, Martínez JL. Ultrastructure of fish cells involved in cellular defences against Saprolegnia infections: evidence of non-leucocytic nature. Dis Aquat Organ 1998; 32:111-117. [PMID: 9696627 DOI: 10.3354/dao032111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Fish cells attached to hyphae were observed in brown trout Salmo trutta L. infected with Saprolegnia parasitica. Earlier studies with light microscopy indicated that these cells were lymphocytes and neutrophils and that they were involved in the defence mechanisms against Saprolegnia infections. However, using electron microscopy, we found these attached cells did not show leucocytic characteristics, but instead shared some ultrastructural features with filament-containing cells. The pressure of a dense mass of cytoplasmic filaments precludes the leucocytic nature of these cells. How these cells could be involved in cellular defences against fungi is discussed.
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Affiliation(s)
- M V López-Dóriga
- Dpto. Biología de Organismos y Sistemas, Universidad de Oviedo, Spain
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38
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Abstract
The possibility of plasmid-encoded quinolone resistance is explored in two model systems. In the first, increasing amounts of wild-type gyrA allele moderately increased minimum inhibitory concentrations to quinolone antibiotics. In the second model, a mutant gyrA allele encoded by a multicopy plasmid produced a quinolone resistance phenotype upon its expression in a quinolone-susceptible Escherichia coli strain.
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Affiliation(s)
- J M Gómez-Gómez
- Servicio de Microbiología, Hospital Ramón y Cajal, Madrid, Spain
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39
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Martínez JL, Penna M. Influences of changes in calcium concentrations, cocaine and clonidine on the cardiac effect of acetaldehyde in rat isolated atria. Gen Pharmacol 1997; 29:281-4. [PMID: 9251914 DOI: 10.1016/s0306-3623(96)00399-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
1. Cardiovascular responses to acetaldehyde (AChO) were investigated in rat isolated atria. 2. Results show that two different doses of AChO (0.29 and 0.88 mM) induce positive inotropic effects on rat atria, and express Ca2+ dependence when analyzed at three external Ca2+ concentrations (0.6, 1.1, 2.2 mM). 3. Cocaine (3.5 and 35 microM) produced significant potentiation of the AChO-positive (0.29 and 0.88 mM) inotropic effect in 1.1 mM Ca2+ medium. 4. Clonidine (40 microM) increased the peak tension developed (PTD) induced by AChO (both 0.29 and 0.88 mM) only 1.1 mM Ca2+ medium. 5. It is suggested that the positive inotropic effect produced by AChO involves a Ca2(+)-dependent mechanism, which can be potentiated by the additional stimulation of alpha-adrenergic receptors.
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Affiliation(s)
- J L Martínez
- Department of Pharmacology, Faculty of Medicine, University of Chile, Santiago, Chile
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40
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Abstract
Two master growth-phase regulatory proteins, H-NS and sigmaS, are involved in the formation of araB-lacZ fusion clones of Escherichia coli MCS2. The stationary-phase sigma factor RpoS is strictly required for the appearance of such mutants, whereas the histone-like protein H-NS represses their emergence. Our results support the idea that genetic changes leading to adaptive mutation in this model system are regulated by physiological signal transduction networks.
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Affiliation(s)
- J M Gómez-Gómez
- Servicio de Microbiologia, Hospital Ramón y Cajal, INSALUD, Madrid, Spain
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41
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Abstract
A cryptic multidrug resistance (MDR) system in Stenotrophomonas maltophilia, the expression of which is selectable by tetracycline, is described. Tetracycline resistance was the consequence of active efflux of the antibiotic, and it was associated with resistance to quinolones and chloramphenicol, but not to aminoglycosides or beta-lactam antibiotics. MDR is linked to the expression of an outer membrane protein (OMP54) both in a model system and in multidrug-resistant clinical isolates.
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Affiliation(s)
- A Alonso
- Banco de Células, Centro Nacional de Biotecnología (CSIC), Campus UAM, Cantoblanco, Madrid, Spain
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42
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Díaz-Guerra M, Esteban M, Martínez JL. Growth of Escherichia coli in acetate as a sole carbon source is inhibited by ankyrin-like repeats present in the 2',5'-linked oligoadenylate-dependent human RNase L enzyme. FEMS Microbiol Lett 1997; 149:107-13. [PMID: 9103982 DOI: 10.1111/j.1574-6968.1997.tb10316.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 02/04/2023] Open
Abstract
Expression of low levels of the 2',5'-linked oligoadenylate-dependent human RNase L, an enzyme induced by interferons, is highly toxic in Escherichia coli. This protein contains an ankyrin domain responsible for RNase L toxicity. The only known ORF in E. coli containing ankyrin repeats is yjaC in the acetate metabolic cluster. We have investigated if expression of mutant forms of RNase L interfere with metabolism of acetate in E. coli. Our findings demonstrate that E. coli expressing RNase L ankyrin repeats is unable to grow in medium containing acetate as the sole carbon source, while it can grow when expressing other domains of the protein. This defect correlates with a severe decrease in the levels of induction of enzymes in the glyoxylate bypass.
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Affiliation(s)
- M Díaz-Guerra
- Centro Nacional de Biotechnología, CSIC, Campus Universidad Autónoma, Madrid, Spain
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43
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Smith KA, Chernova OB, Groves RP, Stark MB, Martínez JL, Davidson JN, Trent JM, Patterson TE, Agarwal A, Duncan P, Agarwal ML, Stark GR. Multiple mechanisms of N-phosphonacetyl-L-aspartate resistance in human cell lines: carbamyl-P synthetase/aspartate transcarbamylase/dihydro-orotase gene amplification is frequent only when chromosome 2 is rearranged. Proc Natl Acad Sci U S A 1997; 94:1816-21. [PMID: 9050862 PMCID: PMC20000 DOI: 10.1073/pnas.94.5.1816] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [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] [Accepted: 12/17/1996] [Indexed: 02/03/2023] Open
Abstract
Rodent cells resistant to N-phosphonacetyl-L-aspartate (PALA) invariably contain amplified carbamyl-P synthetase/aspartate transcarbamylase/dihydro-orotase (CAD) genes, usually in widely spaced tandem arrays present as extensions of the same chromosome arm that carries a single copy of CAD in normal cells. In contrast, amplification of CAD is very infrequent in several human tumor cell lines. Cell lines with minimal chromosomal rearrangement and with unrearranged copies of chromosome 2 rarely develop intrachromosomal amplifications of CAD. These cells frequently become resistant to PALA through a mechanism that increases the aspartate transcarbamylase activity with no increase in CAD copy number, or they obtain one extra copy of CAD by forming an isochromosome 2p or by retaining an extra copy of chromosome 2. In cells with multiple chromosomal aberrations and rearranged copies of chromosome 2, amplification of CAD as tandem arrays from rearranged chromosomes is the most frequent mechanism of PALA resistance. All of these different mechanisms of PALA resistance are blocked in normal human fibroblasts.
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Affiliation(s)
- K A Smith
- Imperial Cancer Research Fund, London, United Kingdom
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44
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Blanco JR, Pérez JL, Martínez K, Martínez JL, Goñi E, Alvarez A, Pérez E, Oteo JA. [Scheduled biliary surgery and antibiotic prophylaxis. Is its use always justified?]. An Med Interna 1997; 14:111-3. [PMID: 9235077] [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] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
AIM Evaluate the need to give prophylactic antibiotic therapy in patients that undergo elective surgery for cholelithiasis. METHODS Prospective study in 35 patients the underwent surgery for cholelithiasis, without infectious risk factors. All of them, the hemocultives, endotoxin and Tumor Necrosis Factor has been evaluated along the surgical process. RESULTS The hemocultives were in all the patients negatives. The levels of Tumor Necrosis Factor decreased along the surgical process, without modifications of endotoxin levels. There were no significant differences in either of the points of the analysis. CONCLUSIONS Biliary surgery in patients that undergo elective surgery for cholelithiasis, without infectious risk factors, is a clean surgery, and so, in this patients is not indicated systematically an antibiotic prophylaxis.
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Affiliation(s)
- J R Blanco
- Servicio de Medicina Interna y Enf. Infecciosas, Hospital de La Rioja
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45
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Martínez JL, Behrens MM, Moratilla C, Renart J. Oleoylanilide, a possible causative agent of toxic oil syndrome, interferes with the cytoskeleton in a neuronal cell line. Neurotoxicol Teratol 1997; 19:147-50. [PMID: 9136131 DOI: 10.1016/s0892-0362(96)00153-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 02/04/2023]
Abstract
We have examined the effects of oleoylanilide, one of the main candidates in the etiology of the toxic oil syndrome, in the neuroblastoma cell line N2A. Oleoylanilide treatment causes two kinds of phenomena: alteration of the actin cytoskeleton, creating a brush-like protrusion of actin at the periphery of the cells, and reduction of the adhesiveness of these cells to laminin and fibronectin, two of the main components of the extracellular matrix in the central nervous system. These effects could be correlated with symptoms shown in the acute and chronic phases of the disease.
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Affiliation(s)
- J L Martínez
- Instituto de Investigaciones Biomédicas del CSIC, Madrid, Spain
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46
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Díliz HS, Juárez H, Evaristo G, Del Pozzo JA, Torres L, Leal V, Martínez JL, Guerrero A, González MA, Guzmán F, Obregón C, Limón A. Canine segmental liver autotransplantation: an experimental training and research model. Transplant Proc 1996; 28:3396-7. [PMID: 8962326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- H S Díliz
- Department of Transplant Surgery, Hospital Central Sur de Alta Especialidad Pemex, Mexico D.F., Mexico
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47
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Evaristo G, Díliz HS, Del Pozzo JA, Martínez JL, López-Conde LR, Xochipiltecatl J, Alvarez L, Zúñiga V. Early surgical treatment of urine leak in renal transplantation. Transplant Proc 1996; 28:3328-9. [PMID: 8962292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- G Evaristo
- Department of Transplant Surgery, Hospital Central Sur de Alta Especialidad Pemex, México DF., México
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48
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Quirce F, Gil VF, Martínez JL, Calduch JV, Orozco D, Merino J. [Quality of drug prescriptions by the Spanish internal medicine services]. An Med Interna 1996; 13:434-7. [PMID: 9132034] [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] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Many registered drugs in different countries not always have been tested by clinical assays and their efficacy has no definitively proved. Good clinical practice must assume the prescription of the more efficacy drugs. The aim of this study is to evaluate the quality of the drugs prescribed by spanish general internists. We analyze the treatments prescribed by general internists using their hospital medical records. The records were offered by the Heads of the Internal Medecine Departments of Spanish hospitals with 250 beds or more when required by the Spanish Society of Internal Medecine. A random sample, stratified by the hospital size, was obtained from the whole of the Spanish hospitals. Quality of the drugs was determined using two criteria: A. Their intrinsic value; it was decided it was high if clinical assays showed their efficacy and security, and low of it was not B. The number of different chemical substances in the drug; we considered a high quality criteria if only one chemical substance, or two with proved synergistic efficacy were present, and low if it was more than two, or without proved synergistic efficacy. The sample was 250 clinical records, with 1022 different prescriptions; the records were collected between February and July 1994. We found that 94.06 +/- 1.45 of evaluated treatments have a high intrinsic value, and 96.93 +/- 1.06 have only one chemical component. The drugs without a high intrinsic value were: oral hypoglycaemics, some including several combinations of vit B, drugs acting on the cerebral blood flow and some mucolitics. Spanish general Internists usually prescribed monocomponent drugs with proved efficacy and safety.
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Affiliation(s)
- F Quirce
- Departamento de Medicina, Universidad de Alicante
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Bermejo FJ, Dawidowski J, Fernández-Perea R, Martínez JL. Anomalous temperature dependence of the first diffraction peak in vitreous boron trioxide. Phys Rev B Condens Matter 1996; 54:244-254. [PMID: 9984252 DOI: 10.1103/physrevb.54.244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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50
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Culebras E, Martínez JL, Baquero F, Pérez-Díaz JC. pH modulation of aminoglycoside resistance in Staphylococcus epidermidis harbouring 6'-N-aminoglycoside acetyltransferase. J Antimicrob Chemother 1996; 37:881-9. [PMID: 8737138 DOI: 10.1093/jac/37.5.881] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 02/01/2023] Open
Abstract
The kinetic constants of the aminoglycoside-modifying enzyme 6'-N-aminoglycoside acetyltransferase (AAC(6')IV) from the clinical strain Staphylococcus epidermidis RYC 13036 differed depending on whether tobramycin and amikacin (glycosamine group) or gentamicin and netilmicin (garosamine group) were used as substrates. Acetylation of the glucosamine antibiotics was highly susceptible to substrate inhibition which increased with pH whereas the garosamine group compounds showed limited substrate inhibition over a wide pH range. These differences in activity correlated with MIC values of S. epidermidis RYC 13036 for different aminoglycosides. Aminosugars moiety and pH markedly influenced the AAC(6')IV-aminoglycoside interactions.
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Affiliation(s)
- E Culebras
- Centro Nacional de Biotecnología,(CSIC), Cantoblanco, Madrid, Spain
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