1,097 results on '"Pedraza, D."'
Search Results
2. Alpha-1 antitrypsin inhibits pertussis toxin.
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Lietz S, Sommer A, Sokolowski LM, Kling C, Rodriguez Alfonso AA, Preising N, Alpízar-Pedraza D, King J, Streit L, Schröppel B, van Erp R, Barth E, Schneider M, Münch J, Michaelis J, Ständker L, Wiese S, Barth H, Pulliainen AT, Scanlon K, and Ernst K
- Abstract
Pertussis (whooping cough) is a vaccine-preventable but re-emerging, highly infectious respiratory disease caused by Bordetella pertussis. There are currently no effective treatments for pertussis, complicating care for non-vaccinated individuals, especially newborns. Disease manifestations are predominantly caused by pertussis toxin (PT), a pivotal virulence factor classified as an ADP-ribosylating AB-type protein toxin. In this work, an unbiased approach using peptide libraries, bioassay-guided fractionation and mass spectrometry revealed α
1 -antitrypsin (α1 AT) as a potent PT inhibitor. Biochemistry-, cell culture- and molecular modeling-based in vitro experimentation demonstrated that the α1 AT mode of action is based on blocking PT-binding to the host target cell surface. In the infant mouse model of severe pertussis, α1 AT expression was reduced upon infection. Further, systemic administration of α1 AT significantly reduced B. pertussis-induced leukocytosis, which is a hallmark of infant infection and major risk factor for fatal pertussis. Taken together our data demonstrates that α1 AT is a novel PT inhibitor and that further evaluation and development of α1 AT as a therapeutic agent for pertussis is warranted. Importantly, purified α1 AT is already in use clinically as an intravenous augmentation therapy for those with genetic α1 AT deficiency and could be repurposed to clinical management of pertussis., Competing Interests: Conflicts of Interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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3. OP07.08: How bad is it to keep selective technique for TTTS?
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Yamamoto, M., primary, Figueroa, H., additional, Pedraza, D., additional, Astudillo, J., additional, Biancardi, S., additional, Rojas, F., additional, and Vergara, V., additional
- Published
- 2023
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4. Designing Polyaniline Films with Tailored Thermal, Optical, and Hydrophobic Properties via Gold Nanoparticle Integration
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Mahadik, Satish A, primary, Fernando, Pedraza D., additional, and Thakur, Sonika, additional
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- 2023
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5. Expert-based collaborative analysis of the situation and prospects of biomarker test implementation in oncology in Spain.
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Mestre-Ferrándiz J, Franch Camino B, Hidalgo Á, Del Llano Núñez-Cortés A, Del Llano Señarís JE, Lumbreras B, Beas Pedraza D, Nuño-Solinís R, Paz-Ares L, Ramón Y Cajal S, and Rodríguez MJ
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- Humans, Spain, Focus Groups, Biomarkers, Tumor analysis, Precision Medicine, Medical Oncology, Neoplasms diagnosis
- Abstract
Purpose: Biomarkers as screening for precision medicine is a fundamental step. The purpose of this article is twofold. First, to highlight the existing barriers in the implementation of Precision Medicine in Spain, with a special emphasis on barriers in access to the determination of biomarkers. Second, to provide a Roadmap that can help implement Precision Medicine equitably at the national level and optimize the use of biomarkers., Methods: A systematic review of literature (SRL) and a focus group (FG) with multidisciplinary experts has been carried out in 2023. Participants were contacted individually, and discourse analysis was processed anonymously., Results: We carried out a quantitative (SRL) and a qualitative approach (FG). The discourse analysis and roadmap were sent individually to each expert for approval., Conclusions: The potential of Precision Medicine has not been fulfilled in Spain. While several regional initiatives are in place, a national plan or strategy around Precision Medicine and use of biomarkers is lacking. In a general context of rapid progress at a global and European level, including the 2021 Europe's Beating Cancer Plan, it is time to define and implement a National Plan to make the promise come true. While some comparable countries within Europe - such as the UK or France - are mature enough to adopt such strategies, in Spain there is still a long way to go. We consider that the different strands of work outlined in the Roadmap can be used as basis for such purpose., (© 2024. The Author(s).)
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- 2024
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6. Pore-forming peptide C14R exhibits potent antifungal activity against clinical isolates of Candida albicans and Candida auris .
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Vélez N, Argel A, Kissmann AK, Alpízar-Pedraza D, Escandón P, Rosenau F, Ständker L, and Firacative C
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- Humans, Candida albicans, Fluconazole pharmacology, Fluconazole therapeutic use, Candida auris, Peptides pharmacology, Microbial Sensitivity Tests, Drug Resistance, Fungal, Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Candidiasis, Invasive, Candidiasis
- Abstract
Introduction: Invasive candidiasis is a global public health problem as it poses a significant threat in hospital-settings. The aim of this study was to evaluate C14R, an analog derived from peptide BP100, as a potential antimicrobial peptide against the prevalent opportunistic yeast Candida albicans and the emergent multidrug-resistant yeast Candida auris ., Methods: Antifungal susceptibility testing of C14R against 99 C . albicans and 105 C . auris clinical isolates from Colombia, was determined by broth microdilution. Fluconazole was used as a control antifungal. The synergy between C14R and fluconazole was assessed in resistant isolates. Assays against fungal biofilm and growth curves were also carried out. Morphological alterations of yeast cell surface were evaluated by scanning electron microscopy. A permeability assay verified the pore-forming ability of C14R., Results: C. albicans and C. auris isolates had a geometric mean MIC against C14R of 4.42 µg/ml and 5.34 µg/ml, respectively. Notably, none of the isolates of any species exhibited growth at the highest evaluated peptide concentration (200 µg/ml). Synergistic effects were observed when combining the peptide and fluconazole. C14R affects biofilm and growth of C. albicans and C. auris . Cell membrane disruptions were observed in both species after treatment with the peptide. It was confirmed that C14R form pores in C. albicans ' membrane., Discussion: C14R has a potent antifungal activity against a large set of clinical isolates of both C. albicans and C. auris , showing its capacity to disrupt Candida membranes. This antifungal activity remains consistent across isolates regardless of their clinical source. Furthermore, the absence of correlation between MICs to C14R and resistance to fluconazole indicates the peptide's potential effectiveness against fluconazole-resistant strains. Our results suggest the potential of C14R, a pore-forming peptide, as a treatment option for fungal infections, such as invasive candidiasis, including fluconazole and amphotericin B -resistant strains., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Vélez, Argel, Kissmann, Alpízar-Pedraza, Escandón, Rosenau, Ständker and Firacative.)
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- 2024
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7. Identification of a potent and selective LAPTc inhibitor by RapidFire-Mass Spectrometry, with antichagasic activity.
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Izquierdo M, Lin, O'Neill S, Webster LA, Paterson C, Thomas J, Aguado ME, Colina Araújo E, Alpízar-Pedraza D, Joji H, MacLean L, Hope A, Gray DW, Zoltner M, Field MC, González-Bacerio J, and De Rycker M
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- Humans, Leucyl Aminopeptidase chemistry, Leucyl Aminopeptidase pharmacology, Leucyl Aminopeptidase therapeutic use, Drug Discovery, Antiparasitic Agents therapeutic use, Trypanosoma cruzi, Chagas Disease drug therapy, Trypanocidal Agents therapeutic use
- Abstract
Background: Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and leads to ~10,000 deaths each year. Nifurtimox and benznidazole are the only two drugs available but have significant adverse effects and limited efficacy. New chemotherapeutic agents are urgently required. Here we identified inhibitors of the acidic M17 leucyl-aminopeptidase from T. cruzi (LAPTc) that show promise as novel starting points for Chagas disease drug discovery., Methodology/principal Findings: A RapidFire-MS screen with a protease-focused compound library identified novel LAPTc inhibitors. Twenty-eight hits were progressed to the dose-response studies, from which 12 molecules inhibited LAPTc with IC50 < 34 μM. Of these, compound 4 was the most potent hit and mode of inhibition studies indicate that compound 4 is a competitive LAPTc inhibitor, with Ki 0.27 μM. Compound 4 is selective with respect to human LAP3, showing a selectivity index of >500. Compound 4 exhibited sub-micromolar activity against intracellular T. cruzi amastigotes, and while the selectivity-window against the host cells was narrow, no toxicity was observed for un-infected HepG2 cells. In silico modelling of the LAPTc-compound 4 interaction is consistent with the competitive mode of inhibition. Molecular dynamics simulations reproduce the experimental binding strength (-8.95 kcal/mol), and indicate a binding mode based mainly on hydrophobic interactions with active site residues without metal cation coordination., Conclusions/significance: Our data indicates that these new LAPTc inhibitors should be considered for further development as antiparasitic agents for the treatment of Chagas disease., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Izquierdo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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8. Insights into the Adsorption Mechanisms of the Antimicrobial Peptide CIDEM-501 on Membrane Models.
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Alpízar-Pedraza D, Roque-Diaz Y, Garay-Pérez H, Rosenau F, Ständker L, and Montero-Alejo V
- Abstract
CIDEM-501 is a hybrid antimicrobial peptide rationally designed based on the structure of panusin and panulirin template peptides. The new peptide exhibits significant antibacterial activity against multidrug-resistant pathogens (MIC = 2-4 μM) while conserving no toxicity in human cell lines. We conducted molecular dynamics (MD) simulations using the CHARMM-36 force field to explore the CIDEM-501 adsorption mechanism with different membrane compositions. Several parameters that characterize these interactions were analyzed to elucidate individual residues' structural and thermodynamic contributions. The membrane models were constructed using CHARMM-GUI, mimicking the bacterial and eukaryotic phospholipid compositions. Molecular dynamics simulations were conducted over 500 ns, showing rapid and highly stable peptide adsorption to bacterial lipids components rather than the zwitterionic eucaryotic model membrane. A predominant peptide orientation was observed in all models dominated by an electric dipole. The peptide remained parallel to the membrane surface with the center loop oriented to the lipids. Our findings shed light on the antibacterial activity of CIDEM-501 on bacterial membranes and yield insights valuable for designing potent antimicrobial peptides targeting multi- and extreme drug-resistant bacteria.
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- 2024
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9. Securing access to a comprehensive diagnostic panel for children with suspected acute lymphoblastic leukemia: Results from the Mexico in Alliance with St. Jude "Bridge Project".
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Friedrich P, Mercado N, Echeandia-Abud N, Guerrero-Gomez K, González-Zamorano M, López-Ruíz MI, Portillo-Zavala CS, García-Segura LD, Reynoso-Gutiérrez M, López-Facundo NA, Cárdenas-Pedraza D, Valois-Escamilla MG, Mera-González AB, Covarrubias-Zapata D, Vollbrechtshausen-Castelán LA, Loeza-Oliva JJ, Garay-Sánchez SA, Moreno-Serrano J, Mendoza-Sánchez P, Casillas-Toral P, Sandoval-Cabrera A, Gutiérrez-Martínez I, Jiménez-Osorio MI, Arce-Cabrera D, Aguilar-Escobar DV, González-Montalvo PM, and Romo-Rubio HA
- Abstract
Background: The "Bridge Project" is a Mexico in Alliance with St. Jude (MAS) initiative developed in 2019 to improve access, accuracy, and timeliness of specialized diagnostic studies for patients with suspected acute lymphoblastic leukemia (ALL). The project strategy relies on service centralization to improve service delivery, biological characterization, risk-group classification, and support proper treatment allocation., Methods: This is an ongoing prospective multisite intersectoral quality improvement (QI) project available to all patients 0-18 years of age presenting with suspected ALL to the 14 actively participating institutions in 12 Mexican states. Institutions send specimens to one centralized laboratory. From a clinical standpoint, the project secures access to a consensus-derived comprehensive diagnostic panel. From a service delivery standpoint, we assess equity, timeliness, effectiveness, and patient-centeredness. From an implementation science standpoint, we document feasibility, utility, and appropriateness of the diagnostic panel and centralized approach. This analysis spans from July 2019 to June 2023., Results: 612 patients have accessed the project. The median age was 6 years (IQR 3-11), and 53% were males. 94% of the specimens arrived within 48 hours, which documents the feasibility of the centralized model, and 100% of the patients received precise and timely diagnostic results, which documents the effectiveness of the approach. Of 505 (82.5%) patients with confirmed ALL, 463/505 (91.6%) had B-cell ALL, and 42/505 (8.3%) had T-cell ALL. High-hyperdiploidy was detected by DNA index in 36.6% and hypodiploidy in 1.6%. 76.6% of the patients had conclusive karyotype results. FISH studies showed t(12;21) in 15%, iAMP21 in 8.5%, t(1;19) in 7.5%, t(4;11) in 4.2%, t(9;22) in 3.2%, del(9)(p21) in 1.8%, and TRA/D (14)(q11.2) rearrangement in 2.4%. Among B-cell ALL patients, 344/403 (85.1%) had Day 15 MRD<1% and 261/305 (85.6%) Day 84 MRD<0.01. For T-cell ALL patients 20/28 (71.4%) had Day 29 MRD<0.01% and 19/22 (86.4%) Day 84 MRD<0.01%., Conclusions: By securing access to a standardized consensus-derived diagnostic panel, the Bridge Project has allowed better characterization of childhood ALL in Mexico while producing unprecedented service improvements and documenting key implementation outcomes. We are using these results to inform iterative changes to the diagnostic panel and an associated treatment guideline (MAS-ALL18)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Friedrich, Mercado, Echeandia-Abud, Guerrero-Gomez, González-Zamorano, López-Ruíz, Portillo-Zavala, García-Segura, Reynoso-Gutiérrez, López-Facundo, Cárdenas-Pedraza, Valois-Escamilla, Mera-González, Covarrubias-Zapata, Vollbrechtshausen-Castelán, Loeza-Oliva, Garay-Sánchez, Moreno-Serrano, Mendoza-Sánchez, Casillas-Toral, Sandoval-Cabrera, Gutiérrez-Martínez, Jiménez-Osorio, Arce-Cabrera, Aguilar-Escobar, González-Montalvo and Romo-Rubio.)
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- 2024
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10. The Designed Pore-Forming Antimicrobial Peptide C14R Combines Excellent Activity against the Major Opportunistic Human Pathogen Pseudomonas aeruginosa with Low Cytotoxicity.
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Mildenberger V, Alpízar-Pedraza D, Martell-Huguet EM, Krämer M, Bolotnikov G, Otero-Gonzalez AJ, Weil T, Rodriguez-Alfonso A, Preising N, Ständker L, Vogel V, Spellerberg B, Kissmann AK, and Rosenau F
- Abstract
The diminishing portfolio of mankind's available antibiotics urges science to develop novel potent drugs. Here, we present a peptide fitting the typical blueprint of amphipathic and membrane-active antimicrobial peptides, denominated C14R. This 2 kDa peptide consists of 16 amino acid residues, with seven being either hydrophobic, aromatic, or non-polar, and nine being polar or positively charged, strictly separated on opposite sides of the predicted α-helix. The affinity of the peptide C14R to P. aeruginosa membranes and its intrinsic tendency to productively insert into membranes of such composition were analyzed by dynamic simulations. Its biological impact on the viability of two different P. aeruginosa reference strains was demonstrated by determining the minimal inhibitory concentrations (MICs), which were found to be in the range of 10-15 µg/mL. C14R's pore-forming capability was verified in a permeabilization assay based on the peptide-triggered uptake of fluorescent dyes into the bacterial cells. Finally, the peptide was used in radial diffusion assays, which are commonly used for susceptibility testing of antimicrobial peptides in clinical microbiology. In comparison to reference strains, six clinical P. aeruginosa isolates were clearly affected, thereby paving the way for further in-depth analyses of C14R as a promising new AMP drug in the future.
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- 2024
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11. EP15.02: Perinatal outcomes of fetuses with nuchal translucency > 99th percentile at 11–14 weeks' scan and normal karyotype: a single Chilean institutional study
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Sepúlveda‐Martínez, A., primary, Elicer, B., additional, Guiñez, J., additional, Socias, P., additional, Guiñez, R., additional, Silva, M., additional, Pedraza, D., additional, Valdes, E., additional, Muñoz, H., additional, and Parra‐Cordero, M., additional
- Published
- 2022
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12. Xanthatin and 8-epi-xanthatin as new potential colchicine binding site inhibitors: a computational study.
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Alpízar-Pedraza D, Veulens AN, Ginarte YMÁ, Piloto-Ferrer J, and Sánchez-Lamar Á
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- Tubulin metabolism, Furans pharmacology, Binding Sites, Microtubules, Colchicine pharmacology, Colchicine chemistry, Antineoplastic Agents pharmacology
- Abstract
Context: Phytocompounds xanthatin and 8-epi-xanthatin, obtained from Xanthium chinese Mill, showed antitumoral activity in vitro related to the microtubules destabilizing properties of these phytocompounds. Five binding sites for microtubule destabilizing agents have been characterized on tubulin by high-resolution X-ray crystallography: vinca domain, colchicine, pironetin, maytansine site, and more recently, the seventh site. This work aims to develop a comprehensive computational strategy to understand and eventually predict the interaction between xanthatin and 8-epi-xanthatin with the destabilizing-antimitotic binding domain of the tubulin heterodimer. In addition, we propose a putative binding site for these phytocompounds into the microtubule destabilizing binding sites on the tubulin heterodimer. Xanthanolides showed higher stability in the colchicine and pironetin binding sites, whit a greater affinity for the former. In addition, we found that xanthanolides and non-classical colchicine binding site inhibitors share a high structural similarity., Methods: The 3D structures for xanthatin and 8-epi-xanthatin were obtained using DFT with the hybrid functional B3LYP and the base 6-31G (d,p), implemented in Gaussian 09. The 3D coordinates for tubulin proteins were downloaded from PDB. The complexes tubulin-xanthanolides were predicted using a Monte-Carlo iterated search combined with the BFGS gradient-based optimizer implemented in the AutoDock Vina. The xanthanolides-tubulin complexes were energy minimized by molecular dynamics simulations at vacuum, and their stabilities were evaluated by solvated molecular dynamics simulations during 100 ns. All molecular dynamics simulations were performed using the conjugate gradient method implemented in NAMD2 and CHARMM36 forcefield., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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13. Durability and restoring of superhydrophobic properties in silica-based coatings
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Mahadik, Satish A., Fernando, Pedraza D., Hegade, Nagaraja D., Wagh, Pratap B., and C. Gupta, Satish
- Published
- 2013
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14. Effects of a Sexual Risk-Reduction Intervention for Teenagers: A Cluster-Randomized Control Trial.
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Gómez-Lugo M, Morales A, Saavedra-Roa A, Niebles-Charris J, Abello-Luque D, Marchal-Bertrand L, García-Roncallo P, García-Montaño E, Pérez-Pedraza D, Espada JP, and Vallejo-Medina P
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- Adolescent, Condoms, Health Knowledge, Attitudes, Practice, Humans, Risk Reduction Behavior, Sexual Behavior, HIV Infections epidemiology, HIV Infections prevention & control, Sexually Transmitted Diseases epidemiology, Sexually Transmitted Diseases prevention & control
- Abstract
This study evaluated the efficacy of the COMPAS program in the short term and 6 months after its application. For the initial sample, 2047 teenagers aged 14-19 years from 14 schools in 11 Colombian cities participated; eight schools were randomly assigned to the experimental condition and six to the control group. The participants completed self-report assessments that evaluated several variables theoretically associated with protective sexual behaviors. In the short term, the experimental group showed increased knowledge about HIV and other STIs, sexual assertiveness, self-efficacy, greater behavioral intention toward condom use, and more favorable attitudes toward HIV and condom use than the control group. After 6 months, most psychological and health variables also showed a significant positive change. In conclusion, the COMPAS program is the first school-based sexuality education program that has been shown to be effective in reducing mediating and behavioral variables associated with sexual risk reduction in Colombia., (© 2022. The Author(s).)
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- 2022
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15. Disordering and Amorphization of Zr3AI by 3.8 MeV Zr3+ Ion Bombardment
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Chen, F. C., Pedraza, D. F., Ardell, A. J., and Yavari, A. R., editor
- Published
- 1992
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16. Is there a role for cervical assessment and uterine artery Doppler in the first trimester of pregnancy as a screening test for spontaneous preterm delivery?
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Parra-Cordero, M., Sepúlveda-Martínez, A., Rencoret, G., Valdés, E., Pedraza, D., and Muñoz, H.
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- 2014
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17. Identification and Characterization of Three New Antimicrobial Peptides from the Marine Mollusk Nerita versicolor (Gmelin, 1791).
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Rodriguez A, Martell-Huguet EM, González-García M, Alpízar-Pedraza D, Alba A, Vazquez AA, Grieshober M, Spellerberg B, Stenger S, Münch J, Kissmann AK, Rosenau F, Wessjohann LA, Wiese S, Ständker L, and Otero-Gonzalez AJ
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- Animals, Humans, Antimicrobial Cationic Peptides pharmacology, Antimicrobial Peptides, Anti-Bacterial Agents pharmacology, Mollusca, Microbial Sensitivity Tests, Anti-Infective Agents pharmacology, Gastropoda
- Abstract
Mollusks have been widely investigated for antimicrobial peptides because their humoral defense against pathogens is mainly based on these small biomolecules. In this report, we describe the identification of three novel antimicrobial peptides from the marine mollusk Nerita versicolor . A pool of N. versicolor peptides was analyzed with nanoLC-ESI-MS-MS technology, and three potential antimicrobial peptides (Nv-p1, Nv-p2 and Nv-p3) were identified with bioinformatical predictions and selected for chemical synthesis and evaluation of their biological activity. Database searches showed that two of them show partial identity to histone H4 peptide fragments from other invertebrate species. Structural predictions revealed that they all adopt a random coil structure even when placed near a lipid bilayer patch. Nv-p1, Nv-p2 and Nv-p3 exhibited activity against Pseudomonas aeruginosa . The most active peptide was Nv-p3 with an inhibitory activity starting at 1.5 µg/mL in the radial diffusion assays. The peptides were ineffective against Klebsiella pneumoniae , Listeria monocytogenes and Mycobacterium tuberculosis . On the other hand, these peptides demonstrated effective antibiofilm action against Candida albicans , Candida parapsilosis and Candida auris but not against the planktonic cells. None of the peptides had significant toxicity on primary human macrophages and fetal lung fibroblasts at effective antimicrobial concentrations. Our results indicate that N. versicolor -derived peptides represent new AMP sequences and have the potential to be optimized and developed into antibiotic alternatives against bacterial and fungal infections.
- Published
- 2023
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18. Social context and moderate-severe food and nutritional insecurity in families with children aged 0-59 months, Paraíba, Brazil, 2017-2018.
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Figueroa-Pedraza D
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- Humans, Child, Brazil epidemiology, Cross-Sectional Studies, Social Support, Socioeconomic Factors, Food Supply, Pediatric Obesity
- Abstract
Objective.: To analyze the association between the social context (demographic, socioeconomic and social support factors) and moderate-severe food and nutritional insecurity in families with children aged 0-59 months enrolled in municipal kindergartens in the state of Paraíba, Brazil., Materials and Methods.: We conducted a cross-sectional study in Brazilian municipalities prioritized for the prevention of childhood obesity. A questionnaire was used to collect information on the social context of the family (demographic profile of the child, socioeconomic situation and social support) as well as the Brazilian food insecurity scale. The association between the independent variables and moderate-severe food and nutrition insecurity was determined by applying Poisson regression to estimate crude and adjusted prevalence ratios and their respective 95% confidence intervals., Results.: We included 382 families; 27.2% had moderate-severe food and nutrition insecurity. In addition, dysfunctional families with children under 24 months, from less affluent classes, beneficiaries of the Bolsa Família Program and without social support (material, emotional/informational and interaction) were more likely to present the outcome., Conclusions.: Our results show that 27.2% of the families had moderate-severe food and nutritional insecurity, were beneficiaries of the Bolsa Família Program, dysfunctional and did not have social support. Therefore, the identification of these factors would be useful to improve family food and nutritional security.
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- 2023
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19. Heart Lung Machine and Extracorporeal Life Support: A Modular System: O69 (EI0005)
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Schlanstein, P. C., Wagner, G., Arens, J., Pedraza, D., Kopp, R., Bensberg, R., Rossaint, R., Schmitz-Rode, T., and Steinseifer, U.
- Published
- 2011
20. VP22.04: 91 consecutive TTTS cases with selective technique
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Yamamoto, M., primary, Pedraza, D., additional, Astudillo, J., additional, and Figueroa, H., additional
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- 2020
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21. Perceived Collective School Efficacy Mediates the Organizational Justice Effect in Teachers' Subjective Well-Being.
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Herrera C, Torres-Vallejos J, Martínez-Líbano J, Rubio A, Céspedes C, Oyanedel JC, Acuña E, and Pedraza D
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- Achievement, Humans, School Teachers, Schools, Organizational Culture, Social Justice
- Abstract
Trust and team communication are central aspects for the achievement of both individual and common goals, which affect not only work efficiency but also the well-being of its members. In addition, organizational justice could affect these indicators, as well as the perception of collective efficacy within organizations, in this case, schools. The purpose of this study was to analyze the effect of organizational justice on teachers' subjective well-being, and how this is affected/mediated by collective efficacy. We worked with a sample of 693 teachers across Chile. Multiple mediation analysis was carried out, where the latent variables of the study were estimated (subjective well-being, organizational justice, and two dimensions of collective efficacy). The results indicate that there is full mediation of the collective efficacy dimensions between the predictor-criterion relationship. Our findings allow us to hypothesize that perceptions of collective efficacy are central to explaining well-being as an intrinsic factor.
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- 2022
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22. Screening for trisomy 21 during the routine second-trimester ultrasound examination in an unselected Chilean population
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PARRA-CORDERO, M., QUIROZ, L., RENCORET, G., PEDRAZA, D., MUÑOZ, H., SOTO-CHACÓN, E., and MIRANDA-MENDOZA, I.
- Published
- 2007
23. Irradiation as a tool for studying solid-state amorphization phenomena
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Pedraza, D. F.
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- 1990
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24. Treatment-refractory heart failure as a manifestation of aortic arch atresia.
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González-Ramos LA, Martínez-Carballo EM, Anaya-García JE, Sánchez-Cárdenas J, Velázquez-Fontes KN, and Mazariego-Pedraza D
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- Adult, Aorta, Thoracic abnormalities, Aorta, Thoracic surgery, Child, Humans, Infant, Newborn, Aortic Arch Syndromes congenital, Aortic Arch Syndromes surgery, Aortic Coarctation diagnosis, Ductus Arteriosus, Patent complications, Ductus Arteriosus, Patent diagnosis, Ductus Arteriosus, Patent surgery, Heart Failure etiology
- Abstract
Background: Distal segment atresia (isthmus) is an extremely rare anatomical variant of obstructive aortic arch anomalies., Case Report: We present the case of a newborn who, at 48 hours of life, presented a clinical picture of heart failure. The initial echocardiogram showed a congenital interrupted aortic arch type A, patent ductus arteriosus, and ventricular septal defect. Prostaglandins were initially indicated. Subsequently, a second echocardiogram showed the absence of ductus arteriosus; the CT angiography study confirmed this finding and revealed blood flow to the descending aorta through small intercostal blood vessels. The possibility of atresia of the distal segment (isthmus) of the aortic arch was considered and confirmed at the time of surgery., Conclusions: Aortic atresia should be considered a diagnostic possibility in the presence of type A interrupted aortic arch since the hemodynamic behavior between them is similar. Surgical medical treatment should be individualized since this condition is frequently an emergency in the neonatal period. However, this is not always the case, as other cases have been reported in schoolchildren and adults., (Copyright: © 2022 Permanyer.)
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- 2022
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25. Toward a More Comprehensive View of α-Amylase across Decapods Crustaceans.
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Rodríguez-Viera L, Alpízar-Pedraza D, Mancera JM, and Perera E
- Abstract
Decapod crustaceans are a very diverse group and have evolved to suit a wide variety of diets. Alpha-amylases enzymes, responsible for starch and glycogen digestion, have been more thoroughly studied in herbivore and omnivore than in carnivorous species. We used information on the α-amylase of a carnivorous lobster as a connecting thread to provide a more comprehensive view of α-amylases across decapods crustaceans. Omnivorous crustaceans such as shrimps, crabs, and crayfish present relatively high amylase activity with respect to carnivorous crustaceans. Yet, contradictory results have been obtained and relatively high activity in some carnivores has been suggested to be a remnant trait from ancestor species. Here, we provided information sustaining that high enzyme sequence and overall architecture conservation do not allow high changes in activity, and that differences among species may be more related to number of genes and isoforms, as well as transcriptional and secretion regulation. However, recent evolutionary analyses revealed that positive selection might have also occurred among distant lineages with feeding habits as a selection force. Some biochemical features of decapod α-amylases can be related with habitat or gut conditions, while less clear patterns are observed for other enzyme properties. Likewise, while molt cycle variations in α-amylase activity are rather similar among species, clear relationships between activity and diet shifts through development cannot be always observed. Regarding the adaptation of α-amylase to diet, juveniles seem to exhibit more flexibility than larvae, and it has been described variation in α-amylase activity or number of isoforms due to the source of carbohydrate and its level in diets, especially in omnivore species. In the carnivorous lobster, however, no influence of the type of carbohydrate could be observed. Moreover, lobsters were not able to fine-regulate α-amylase gene expression in spite of large changes in carbohydrate content of diet, while retaining some capacity to adapt α-amylase activity to very low carbohydrate content in the diets. In this review, we raised arguments for the need of more studies on the α-amylases of less studied decapods groups, including carnivorous species which rely more on dietary protein and lipids, to broaden our view of α-amylase in decapods crustaceans.
- Published
- 2021
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26. OP18.07: Survival prediction of fetuses with congenital diaphragmatic hernia in Chile
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Yamamoto, M., primary, Figueroa, H., additional, Diaz, R., additional, Jimenez, J., additional, Pedraza, D., additional, Astudillo, J., additional, and Deprest, J., additional
- Published
- 2018
- Full Text
- View/download PDF
27. OP15.02: Postnatal follow-up of selective IUGR type 3 without fetal surgery
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Yamamoto, M., primary, Figueroa, H., additional, Pedraza, D., additional, and Astudillo, J., additional
- Published
- 2018
- Full Text
- View/download PDF
28. OC18.02: Umbilical artery (UA) PI in donors is related to hypovolemia
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Yamamoto, M., primary, Figueroa, H., additional, Marfull, C., additional, Pedraza, D., additional, Astudillo, J., additional, and Ville, Y., additional
- Published
- 2018
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- View/download PDF
29. Colombian Adaptation of the HIV and Other Sexually Transmitted Infections Knowledge Scale (KSI) in an Adolescent Population.
- Author
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Abello-Luque D, Espada JP, García-Montaño E, Gómez-Lugo M, Morales A, Pérez-Pedraza D, and Vallejo-Medina P
- Subjects
- Adolescent, Adult, Child, Colombia epidemiology, Female, Health Knowledge, Attitudes, Practice, Humans, Male, Pregnancy, Sexual Behavior, Young Adult, Acquired Immunodeficiency Syndrome, Adolescent Behavior, Sexually Transmitted Diseases epidemiology
- Abstract
Colombia has one of the highest rates of sexually transmitted infections (STIs) and teenage pregnancies among Latin American countries. Knowledge about HIV/AIDS and other STIs has been identified as a factor in promoting healthy sexual behavior. The HIV and Other Sexually Transmitted Infections Knowledge Scale (KSI) is an instrument created in Spain to assess sexual health knowledge in adolescents. In view of the lack of scales that measure this construct in Colombia, this study aims to culturally adapt and validate the KSI for the Colombian adolescent population. The sample was comprised of 866 adolescent school children (458 females and 408 males) aged between 14 and 19 years ( M = 15.97, SD = 1.36) from 12 schools in the cities of Bogotá (n = 467) and Barranquilla (n = 400). Results showed good item psychometric properties and adequate discrimination and difficulty indices. Factorial analysis confirmed a five-dimensional factor structure. The indicators of validity showed significant correlations with constructs related on theoretical grounds. In sum, the study presents a valid and reliable scale for evaluating knowledge about HIV and other STIs in Colombian adolescent population.
- Published
- 2021
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- View/download PDF
30. Durability and restoring of superhydrophobic properties in silica-based coatings
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Pedraza D. Fernando, Satish C. Gupta, Satish A. Mahadik, Nagaraja D. Hegade, and P. B. Wagh
- Subjects
Hot Temperature ,Materials science ,Surface Properties ,engineering.material ,Dip-coating ,Phase Transition ,Biomaterials ,Contact angle ,Colloid and Surface Chemistry ,Coating ,Superhydrophilicity ,Materials Testing ,Spectroscopy, Fourier Transform Infrared ,Composite material ,Temperature ,Hydrogen-Ion Concentration ,Silicon Dioxide ,Durability ,Superhydrophobic coating ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Microscopy, Electron, Scanning ,Wettability ,engineering ,Surface modification ,Glass ,Wetting ,Acids ,Hydrophobic and Hydrophilic Interactions ,Biotechnology - Abstract
The durability and restorable properties of superhydrophobicity are a most important issue essential for utilization of superhydrophobic materials in industrial and domestic fields. In this work, we have focused on the sol–gel dip coating synthesis, durability, and restoring properties of a superhydrophobic surface composed of spherical silica particles with low energy free surface successfully achieved on the surface of glass substrates. The water contact angle (WCA) of the as-prepared superhydrophobic coatings reached as high as 170 ± 1° (WCA = 170 ± 1°) and the sliding angle was 3 ± 1° (WSA = 3 ± 1°). The behavior of wettability on superhydrophobic coating surface under various external disturbances including outdoor environments, heat, and mild acidic condition is investigated. It is shown in particular that degradation and repairing of surface methyl groups between two such surfaces leads to a fully restorable coating surface by the surface modification with trimethylchlorosilane (TMCS) at room temperature. The coating also holds good thermal stability; it holds superhydrophobicity up to 550 °C and gets degrade into superhydrophilicity above 600 °C without deforming surface morphology. The results confirm the durability of the silica coating under different external disturbances and sol–gel dip coating method and restoring property provide the best solution to fabricate superhydrophobic silica coating surface with extended durability at low cost.
- Published
- 2013
31. EP20.07: 111 TTTS cases treated in Talca and Santiago with classical selective technique: towards a Chilean perinatal network
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Yamamoto, M., primary, Becker, J., additional, Araneda, M., additional, De Martini, F., additional, Illanes, S., additional, Pedraza, D., additional, Astudillo, J., additional, and Figueroa, H., additional
- Published
- 2017
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- View/download PDF
32. OP26.08: 25% of fetal interposition (FI) in the placental equator in TTTS placentas: the fetoscopical approach
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Yamamoto, M., primary, Figueroa, H., additional, Jacobsen, M., additional, Diaz, E., additional, Astudillo, J., additional, Pedraza, D., additional, and Ville, Y., additional
- Published
- 2017
- Full Text
- View/download PDF
33. The cis-encoded antisense RNA IsrA from Salmonella Typhimurium represses the expression of STM0294.1n (iasE), an SOS-induced gene coding for an endoribonuclease activity.
- Author
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Acuña LG, Barros MJ, Nuñez P, Peñaloza D, Montt F, Pedraza D, Crossley K, Gil F, Fuentes JA, and Calderón IL
- Subjects
- Amino Acid Sequence, Antitoxins genetics, Bacterial Toxins genetics, Endoribonucleases metabolism, Gene Expression Regulation, Bacterial, Mitomycin metabolism, Models, Molecular, Mutation, Open Reading Frames genetics, Protein Conformation, Protein Folding, Bacterial Proteins genetics, RNA, Antisense genetics, RNA, Bacterial genetics, SOS Response, Genetics genetics, Salmonella typhimurium genetics
- Abstract
Toxin-antitoxin systems are known to be involved in many bacterial functions that can lead to growth arrest and cell death in response to stress. Typically, toxin and antitoxin genes of type I systems are located in opposite strands, where the antitoxin is a small antisense RNA (sRNA). In the present work we show that the sRNA IsrA from Salmonella Typhimurium down-regulates the expression of its overlapping gene STM0294.1n. Multiple sequence alignment and comparative structure analysis indicated that STM0294.1n belongs to the SymE toxin superfamily, and the gene was renamed iasE (IsrA-overlapping gene with similarity to SymE). The iasE expression was induced in response to mitomycin C, an SOS-inducing agent; conversely, IsrA overexpression repressed the iasE expression even in the presence of mitomycin C. Accordingly, the inactivation of IsrA with an anti-IsrA RNA expressed in trans abrogated the repressive effect of IsrA on the iasE expression. On the other hand, iasE overexpression, as well as the blockage of the antisense IsrA function, negatively affected bacterial growth, arguing for a toxic effect of the iasE gene product. Besides, a bacterial lysate obtained from the iasE-overexpressing strain exhibited endoribonuclease activity, as determined by a fluorometric assay based on fluorescent reporter RNAs. Together, these results indicate that the IasE/IsrA pair of S. Typhimurium constitutes a functional type I toxin-antitoxin system., Competing Interests: Declaration of competing interest None declared., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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34. A text mining approach for adapting a school-based sexual health promotion program in Colombia.
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Vallejo-Medina P, Correa JC, Gómez-Lugo M, Saavedra-Roa DA, García-Montaño E, Pérez-Pedraza D, Niebles-Charris J, García-Roncallo P, Abello-Luque D, Espada JP, and Morales A
- Abstract
A common practice among clinical psychologists and other health professionals is the use of school-based sexual health promotion programs as a means for preventing sexually transmitted infections. A fundamental criterion for the designing and adaptation of these programs is the age of their target populations because limited education and language are the most relevant factors that limit the efficacy of these programs. The contribution of this paper consists of assessing both the readability of the written materials that accompany the contents of a Spanish-written school-based sexual health promotion program used in Colombia, as well as the words co-occurrence network structure of its contents. The readability of the evaluated program corresponded to its intended target population aged between 14 and 19, with the schooling of 9-13 years of education. The resulting words co-occurrence network structure of the COMPAS program also mirrored its theoretical content. These results all together are deemed as empirical evidence of the adequacy of the program., (© 2020 The Authors. Published by Elsevier Inc.)
- Published
- 2020
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35. EP04.07: Case report: double aortic arch – two cases
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Muñoz, H., primary, Copado, Y., additional, Munoz, G., additional, Enriquez, G., additional, Pedraza, D., additional, Vera, D., additional, and Parra‐Cordero, M., additional
- Published
- 2016
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- View/download PDF
36. P08.08: Sonographic diagnosis and surgical repair of cervical tear in mid‐trimester
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Yamamoto, M., primary, Carrillo, J., additional, Pedraza, D., additional, and Astudillo, J., additional
- Published
- 2016
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- View/download PDF
37. P30.09: Case report: prenatal diagnosis of intracranial aneurysm
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Muñoz, H., primary, Copado, Y., additional, Munoz, G., additional, Rencoret, G.I., additional, Ortega, X., additional, Galvez, M., additional, Pedraza, D., additional, Vera, D., additional, and Parra‐Cordero, M., additional
- Published
- 2016
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- View/download PDF
38. P13.10: Outcomes in fetuses with agenesis of ductus venosus
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Muñoz, H., primary, Copado, Y., additional, Munoz, G., additional, Rencoret, G.I., additional, Diaz, C., additional, Enriquez, G., additional, Ortega, X., additional, Pedraza, D., additional, Vera, D., additional, and Parra‐Cordero, M., additional
- Published
- 2016
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- View/download PDF
39. P06.11: Case report: fetal cardiac aneurysm
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Muñoz, H., primary, Munoz, G., additional, Copado, Y., additional, Aguilera, S., additional, Enriquez, G., additional, Rencoret, G.I., additional, Diaz, C., additional, Pedraza, D., additional, Vera, D., additional, and Parra‐Cordero, M., additional
- Published
- 2016
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- View/download PDF
40. P06.10: Fetal cardiac tumours, diagnosis and prognosis
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Muñoz, H., primary, Munoz, G., additional, Copado, Y., additional, Aguilera, S., additional, Enriquez, G., additional, Rencoret, G.I., additional, Ortega, X., additional, Pedraza, D., additional, Vera, D., additional, and Parra‐Cordero, M., additional
- Published
- 2016
- Full Text
- View/download PDF
41. On the use of analytic approximations for describing the macroscopic heat flow during solidification
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Pedraza, A. J., Harriague, S., and Fainstein-Pedraza, D.
- Published
- 1980
- Full Text
- View/download PDF
42. The effect of vitamin A supplementation on retinol concentrations of children with anaemia
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Paiva, A. A., Rondo, P. H. C., Reinaldo, L. G. C., Pedraza, D. F., and Ruz, M.
- Published
- 2012
43. EP01.38: Perinatal outcomes of pregestational hypertension according to blood pressure range at 11–14‐week scan: impact of the 2017 ACC/AHA guidelines.
- Author
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Sepúlveda‐Martínez, A., Conrads, T., Guiñez, R., Guiñez, J., Muñoz, H., Valdes, E., Silva, M., Pedraza, D., Llancaqueo, M., and Parra‐Cordero, M.
- Abstract
To evaluate the impact on perinatal outcomes related with placental insufficiency, by the application of the new 2017 ACC/AHA guidelines to a group of chronic hypertensive pregnancies during their first trimester assessment. The best multivariate predictive model for p-PE included a previous PE background (OR = 15) and mean arterial pressure in mmHg (OR = 1.1). EP01.38: Perinatal outcomes of pregestational hypertension according to blood pressure range at 11-14-week scan: impact of the 2017 ACC/AHA guidelines. [Extracted from the article]
- Published
- 2022
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- View/download PDF
44. Principios de evaluación y resultados funcionales en los reimplantes de miembro superior
- Author
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Camporro Fernández, D., Barrio, L., García del Pozo, E., Contreras Pedraza, D., and Matarranz Faya, A.
- Subjects
Amputación miembro superior ,Upper limb replantation ,Upper limb amputation ,Reimplante miembro superior - Abstract
El objetivo de este trabajo es evaluar nuestros resultados funcionales y subjetivos en pacientes sometidos a reimplante de miembro superior. Medimos rango de movilidad articular, fuerza de la prensión y otros tests en 41 pacientes con edad media 44,8 años que sufrieron amputación de miembro superior y fueron sometidos a reimplante quirúrgico en nuestro hospital entre enero del 2005 y diciembre del 2009. Los resultados funcionales se midieron con la tabla de Mayo modificada para lesiones de pulgar, dedos largos y mano, distal a muñeca. Las amputaciones proximales a muñeca se evaluaron según los criterios de Chen. Los resultados subjetivos fueron documentados aplicando a todos los casos el cuestionario de Russell. La mayoría de las lesiones fueron provocadas por mecanismos de avulsión y 30 (74 %) fueron accidentes laborales. La tasa final de supervivencia fue del 85 % (35 pacientes) incluyendo 2 pacientes en los que se realizó trasplante de pie a mano para salvar la amputación. Aplicando la tabla de Mayo modificada, los resultados fueron buenos en pulgar y discretos en mano y dedos largos. En reimplantes proximales obtuvimos 1 resultado excelente y 2 discretos. Diecinueve pacientes retornaron al mundo laboral en una media de 10 meses. Veintisiete manifiestan satisfacción alta con los resultados obtenidos. Los resultados de cualquier reimplante deben superar los del cierre simple de una amputación. Aunque los resultados objetivos de la serie son moderados, muchos pacientes retornan al trabajo y la mayoría es capaz de realizar sus actividades cotidianas. The aim of this study was to evaluate functional and subjective outcome after upper limb replantation, with assessment or range of motions, grip strength, and additional functional tests. Forty-one patients, mean age 44.8 years old, with upper limb amputations were treated in our hospital with replantation between January 2005 and December 2009. Functional results were assessed by modified Mayo scoring system for thumb, fingers and hand amputations. Proximal amputations were evaluated according to the criteria of Chen. Subjective results were documented in all patients by Russell´s Questionnaire. Most of the injuries were caused by avulsion forces and 30 (74 %) were work related. The final survival rate was 85 % (35 patients); we include 2 patients who have had immediate foot transplantations. Using modified Mayo score system the outcome was good in thumb patients and fair in fingers and hand amputations. According to Chen´s criteria the result was excellent in 1 forearm amputation and fair in 2 patients. Nineteen patients had returned to work, their time-off work averaged was 10 months. Patient satisfaction was rated as better than expected and satisfactory in 27 patients. Outcomes of replantation must be better than revision amputation. Although functional outcomes were moderate, most of patients were able to use their hands to perform some work and daily living activities.
- Published
- 2012
45. The effect of vitamin A supplementation on retinol concentrations of children with anaemia
- Author
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Paiva,A. A., Rondo,P. H. C., Reinaldo,L. G. C., Pedraza,D. F., and Ruz,M.
- Published
- 2012
46. P11.06: 67 TTTS cases treated in a single centre in Santiago with classical selective technique
- Author
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Yamamoto, M., primary, Walker Labarca, B., additional, Fleiderman, J., additional, Pedraza, D., additional, and Astudillo, J., additional
- Published
- 2015
- Full Text
- View/download PDF
47. First trimester screening for preterm and term pre-eclampsia by maternal characteristics and biophysical markers in a low-risk population.
- Author
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Sepúlveda-Martínez A, Rencoret G, Silva MC, Ahumada P, Pedraza D, Muñoz H, Valdés E, and Parra-Cordero M
- Subjects
- Adult, Biomarkers, Case-Control Studies, Female, Humans, Pre-Eclampsia diagnostic imaging, Pre-Eclampsia physiopathology, Pregnancy, Pregnancy Trimester, First, Prognosis, Ultrasonography, Doppler, Color, Ultrasonography, Doppler, Pulsed, Arterial Pressure physiology, Pre-Eclampsia diagnosis, Uterine Artery diagnostic imaging
- Abstract
Aim: To develop a combined predictive model for preterm and term pre-eclampsia (PE) during the first trimester of pregnancy., Methods: This investigation was a nested case-control study in singleton pregnancies at the Maternal-Fetal Medicine Unit, University of Chile Hospital. A priori risks for preterm and term PE were calculated by multivariate logistic regression analyses. Biophysical markers were log
10 -transformed and expressed as multiples of the median. A multivariate logistic regression analysis was used to estimate a combined predictive model of preterm and term PE. Detection rates at different cut-off points were determined by a receiver operator curve analysis of a posteriori risks., Results: First trimester mean arterial pressure and uterine artery Doppler pulsatility index were significantly higher in women who develop PE than in the unaffected group. The detection rate of preterm PE based on maternal characteristics and biophysical markers was 72% at a 10% false-positive rate, corresponding to a cut-off risk of 1 in 50. The detection rate for term PE was 30% at a 10% false-positive rate., Conclusion: Preterm PE can be predicted by a combination of maternal characteristics and biophysical markers. However, first trimester screening is less valuable for term PE., (© 2018 Japan Society of Obstetrics and Gynecology.)- Published
- 2019
- Full Text
- View/download PDF
48. Sexual risk among Colombian adolescents: knowledge, attitudes, normative beliefs, perceived control, intention, and sexual behavior.
- Author
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Morales A, Vallejo-Medina P, Abello-Luque D, Saavedra-Roa A, García-Roncallo P, Gomez-Lugo M, García-Montaño E, Marchal-Bertrand L, Niebles-Charris J, Pérez-Pedraza D, and Espada JP
- Subjects
- Adolescent, Colombia, Condoms statistics & numerical data, Cross-Sectional Studies, Female, HIV Infections, Humans, Male, Risk Factors, Sex Factors, Sexually Transmitted Diseases, Young Adult, Adolescent Behavior psychology, Health Knowledge, Attitudes, Practice, Intention, Internal-External Control, Risk-Taking, Sexual Behavior psychology
- Abstract
Background: Colombia has one of the highest rates of the human immunodeficiency virus (HIV) and pregnancies - both of which are influenced by lack of condom use -, among adolescent population in Latin America; however, the mechanisms underlying the inconsistent use of condoms in this population are poorly understood. This descriptive and cross-sectional study's purpose was to examine sexual behavior and its precursors using the theory of planned behavior (TPB) and considering gender-based differences. Another objective was to study the mediating effect of intention in the relationship between behavior precursors and condom use based on the TPB., Methods: We recruited 1100 adolescents aged between 14 and 19 years old (M = 15.94, SD = 1.30, 54.4% female) from Bogotá and Barranquilla, two of the cities with highest adolescent birth rates among adolescents in Colombia. Sociodemographic variables, knowledge on HIV and other sexually transmitted infections (STIs), HIV/AIDS-related attitudes, including attitudes toward the use of condoms, normative beliefs, perceived behavioral control, behavioral intention, and sexual behavior were assessed using self-reports. All analyses were run using SPSS v25. The indirect effect of intention to explain the relationship between precursors and the use of condoms during sexual intercourse was estimated using the PROCESS v3 macro., Results: Descriptive analyses suggest a high risk of contracting sexually transmitted infections and unplanned pregnancies associated to inconsistent condom use, medium-low level of knowledge about sexual health, low normative beliefs regarding peers' condom use, and a certain perceived difficulty for using condoms. Condoms are used 71% of the times they have sex, but only 22% of the participants use them consistently; girls use condoms more consistently than boys. Sexual risk characteristics differed significantly by gender. Mediation analyses indicated that condom use intention mediates the relationship between behavioral precursors and frequency of condom use, according to the TPB., Conclusions: Findings provide a better understanding of sexual risk and highlight important implications for the sexual and reproductive health of adolescents. There is a need of designing and implementing protocolized sexual health promotion programs in schools with the aim of reducing sexual risk behaviors in Colombian adolescents.
- Published
- 2018
- Full Text
- View/download PDF
49. Analytic Approximations for Describing the Irradiation Growth of Zirconium-Base Alloys (II)
- Author
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Pedraza, A. J ., primary and Fainstein-Pedraza, D, additional
- Published
- 1981
- Full Text
- View/download PDF
50. Antibiofilm activity of mesoporous silica nanoparticles against the biofilm associated infections.
- Author
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Sil M, Mukherjee D, Goswami A, Nag M, Lahiri D, and Bhattacharya D
- Subjects
- Humans, Animals, Porosity, Drug Carriers chemistry, Drug Delivery Systems, Bacterial Infections drug therapy, Bacterial Infections microbiology, Quorum Sensing drug effects, Bacteria drug effects, Biofilms drug effects, Silicon Dioxide chemistry, Nanoparticles, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents administration & dosage
- Abstract
In pharmaceutical industries, various chemical carriers are present which are used for drug delivery to the correct target sites. The most popular and upcoming drug delivery carriers are mesoporous silica nanoparticles (MSN). The main reason for its popularity is its ability to be specific and optimize the drug delivery process in a controlled manner. Nowadays, MSNs are widely used to eradicate various microbial infections, especially the ones related to biofilms. Biofilms are sessile groups of cells that live by forming a consortium and exhibit antibacterial resistance (AMR). They exhibit AMR by extracellular polymeric substances (EPS) and various quorum sensing (QS) signaling molecules. Usually, bacterial and fungal cells are capable of forming biofilms. These biofilms are pathogenic. In the majority of the cases, biofilms cause nosocomial diseases. This review will focus on the antibiofilm activities of MSN, its mechanism of target-specific drug delivery, and its ability to disrupt the bacterial biofilms inhibiting the infection. The review will also discuss various mechanisms for the delivery of pharmaceutical molecules by the MSNs to inhibit the bacterial biofilms, and lastly, we will talk about the different types of MSNs and their antibiofilm activities., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2024
- Full Text
- View/download PDF
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