58 results on '"García MN"'
Search Results
2. Studies on semduramicin and nutritional responses: 3. Electrolyte balance
- Author
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Pesti, GM, Cervantes, H, Bakalli, RI, Bafundo, KW, and Garcia, MN
- Published
- 1999
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3. Impairment-Factor-Based Audiovisual Quality Model for IPTV: Influence of Video Resolution, Degradation Type, and Content Type
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Garcia MN, Schleicher R, and Raake A
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Electronics ,TK7800-8360 - Abstract
This paper presents an audiovisual quality model for IPTV services. The model estimates the audiovisual quality of standard and high definition video as perceived by the user. The model is developed for applications such as network planning and packet-layer quality monitoring. It mainly covers audio and video compression artifacts and impairments due to packet loss. The quality tests conducted for model development demonstrate a mutual influence of the perceived audio and video quality, and the predominance of the video quality for the overall audiovisual quality. The balance between audio quality and video quality, however, depends on the content, the video format, and the audio degradation type. The proposed model is based on impairment factors which quantify the quality-impact of the different degradations. The impairment factors are computed from parameters extracted from the bitstream or packet headers. For high definition video, the model predictions show a correlation with unknown subjective ratings of 95%. For comparison, we have developed a more classical audiovisual quality model which is based on the audio and video qualities and their interaction. Both quality- and impairment-factor-based models are further refined by taking the content-type into account. At last, the different model variants are compared with modeling approaches described in the literature.
- Published
- 2011
4. Novel hippocampus-centered methodology for informative instance selection in Alzheimer's disease data.
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Castro-Silva JA, Moreno-García MN, Guachi-Guachi L, and Peluffo-Ordóñez DH
- Abstract
The quantity and quality of a dataset play a crucial role in the performance of prediction models. Increasing the amount of data increases the computational requirements and can introduce negligible variations, outliers, and noise. These significantly impact the model performance. Thus, instance selection techniques are crucial for building prediction models with informative data, reducing the dataset size, improving performance, and minimizing computational costs. This study proposed a novel methodology for identifying the most informative two-dimensional slices derived from magnetic resonance imaging (MRI) to study Alzheimer's disease. The efficacy of our methodology was attributable to a hippocampus-centered analysis using data from multiple atlases. The methodology was evaluated by constructing convolutional neural networks to identify Alzheimer's disease, using a consolidated dataset constructed from three standard datasets: Alzheimer's Disease Neuroimaging Initiative, Australian Imaging, Biomarker & Lifestyle Flagship Study of Ageing, and Open Access Series of Imaging Studies. The proposed methodology demonstrated a commendable subject-level classification accuracy of approximately ( 95.00 % ) when distinguishing between normal cognition and Alzheimer's., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)
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- 2024
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5. HIV Modulates Osteoblast Differentiation via Upregulation of RANKL and Vitronectin.
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Freiberger RN, López CAM, Palma MB, Cevallos C, Sviercz FA, Jarmoluk P, García MN, Quarleri J, and Delpino MV
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Bone loss is a prevalent characteristic among people with HIV (PWH). We focused on mesenchymal stem cells (MSCs) and osteoblasts, examining their susceptibility to different HIV strains (R5- and X4-tropic) and the subsequent effects on bone tissue homeostasis. Our findings suggest that MSCs and osteoblasts are susceptible to R5- and X4-tropic HIV but do not support productive HIV replication. HIV exposure during the osteoblast differentiation process revealed that the virus could not alter mineral and organic matrix deposition. However, the reduction in runt-related transcription factor 2 (RUNX2) transcription, the increase in the transcription of nuclear receptor activator ligand kappa B (RANKL), and the augmentation of vitronectin deposition strongly suggested that X4- and R5-HIV could affect bone homeostasis. This study highlights the HIV ability to alter MSCs' differentiation into osteoblasts, critical for maintaining bone and adipose tissue homeostasis and function.
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- 2024
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6. Comparison of ddRADseq and EUChip60K SNP genotyping systems for population genetics and genomic selection in Eucalyptus dunnii (Maiden).
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Aguirre NC, Villalba PV, García MN, Filippi CV, Rivas JG, Martínez MC, Acuña CV, López AJ, López JA, Pathauer P, Palazzini D, Harrand L, Oberschelp J, Marcó MA, Cisneros EF, Carreras R, Martins Alves AM, Rodrigues JC, Hopp HE, Grattapaglia D, Cappa EP, Paniego NB, and Marcucci Poltri SN
- Abstract
Eucalyptus dunnii is one of the most important Eucalyptus species for short-fiber pulp production in regions where other species of the genus are affected by poor soil and climatic conditions. In this context, E. dunnii holds promise as a resource to address and adapt to the challenges of climate change. Despite its rapid growth and favorable wood properties for solid wood products, the advancement of its improvement remains in its early stages. In this work, we evaluated the performance of two single nucleotide polymorphism, (SNP), genotyping methods for population genetics analysis and Genomic Selection in E. dunnii . Double digest restriction-site associated DNA sequencing (ddRADseq) was compared with the EUChip60K array in 308 individuals from a provenance-progeny trial. The compared SNP set included 8,011 and 19,008 informative SNPs distributed along the 11 chromosomes, respectively. Although the two datasets differed in the percentage of missing data, genome coverage, minor allele frequency and estimated genetic diversity parameters, they revealed a similar genetic structure, showing two subpopulations with little differentiation between them, and low linkage disequilibrium. GS analyses were performed for eleven traits using Genomic Best Linear Unbiased Prediction (GBLUP) and a conventional pedigree-based model (ABLUP). Regardless of the SNP dataset, the predictive ability (PA) of GBLUP was better than that of ABLUP for six traits (Cellulose content, Total and Ethanolic extractives, Total and Klason lignin content and Syringyl and Guaiacyl lignin monomer ratio). When contrasting the SNP datasets used to estimate PAs, the GBLUP-EUChip60K model gave higher and significant PA values for six traits, meanwhile, the values estimated using ddRADseq gave higher values for three other traits. The PAs correlated positively with narrow sense heritabilities, with the highest correlations shown by the ABLUP and GBLUP-EUChip60K. The two genotyping methods, ddRADseq and EUChip60K, are generally comparable for population genetics and genomic prediction, demonstrating the utility of the former when subjected to rigorous SNP filtering. The results of this study provide a basis for future whole-genome studies using ddRADseq in non-model forest species for which SNP arrays have not yet been developed., 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 Aguirre, Villalba, García, Filippi, Rivas, Martínez, Acuña, López, López, Pathauer, Palazzini, Harrand, Oberschelp, Marcó, Cisneros, Carreras, Martins Alves, Rodrigues, Hopp, Grattapaglia, Cappa, Paniego and Marcucci Poltri.)
- Published
- 2024
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7. Therapeutic Potential in Wound Healing of Allogeneic Use of Equine Umbilical Cord Mesenchymal Stem Cells.
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Iribarne A, Palma MB, Andrini L, Riccillo F, Rodriguez D, Casella M, Garay F, Zabala JS, Mazza L, Muro A, Buero G, Miriuka SG, Carosella E, and García MN
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- Animals, Horses, Mice, Leukocytes, Mononuclear, Umbilical Cord, Cicatrix, Mesenchymal Stem Cells, Hematopoietic Stem Cell Transplantation
- Abstract
Wound healing after skin injury is a complex process, particularly in equines where leg wounds are prevalent and their repair is complicated due to the anatomical characteristics. Conventional treatments are not effective enough. The umbilical cord offers an unlimited source of adult mesenchymal stem cells (ucMSCs) from Wharton's jelly tissue. The present study aims to demonstrate the safety and therapeutic potential of the allogeneic use of equine ucMSCs (e-ucMSCs) in the healing of severe equine leg wounds. The methods employed were the isolation, culture and expansion of e-ucMSCs. Flow cytometry and a PCR assay were used for cell characterization. This study included an immunomodulation assay, a murine pre-clinical trial and the first phase of an equine clinical trial. Our results showed that e-ucMSCs express a functional HLA-G homolog, EQMHCB2. In the immunomodulation assay, the e-ucMSCs inhibited the proliferation of activated equine peripheral blood mononuclear cells (e-PBMCs). In the murine pre-clinical trial, e-ucMSCs reduced healing time by 50%. In the equine clinical trial, the injection of e-ucMSCs into severe leg lesions improved the closure time and quality of the tissues involved, regenerating them without fibrous tissue scar formation. In conclusion, the results of this study suggest that e-ucMSCs can be used allogeneically for wound healing by creating a tolerogenic environment.
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- 2024
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8. Genetic manipulation of protein phosphatase 2A affects multiple agronomic traits and physiological parameters in potato ( Solanum tuberosum ).
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Muñiz García MN, Baroli I, Cortelezzi JI, Zubillaga M, and Capiati DA
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- Plant Proteins genetics, Plant Proteins metabolism, Protein Phosphatase 2 genetics, Protein Phosphatase 2 metabolism, Plants, Genetically Modified genetics, Plants, Genetically Modified metabolism, Water metabolism, Sucrose metabolism, Solanum tuberosum genetics
- Abstract
In this study, agronomic and functional characteristics of potato (Solanum tuberosum ) plants constitutively overexpressing the protein phosphatase 2A (PP2A) catalytic subunit StPP2Ac2b (StPP2Ac2b-OE) were evaluated. StPP2Ac2b-OE plants display reduced vegetative growth, tuber yield and tuber weight under well-watered and drought conditions. Leaves of StPP2Ac2b-OE plants show an increased rate of water loss, associated with an impaired ability to close stomata in response to abscisic acid. StPP2Ac2b-OE lines exhibit larger stomatal size and reduced stomatal density. These altered stomatal characteristics might be responsible for the impaired stomatal closure and the elevated transpiration rates, ultimately leading to increased sensitivity to water-deficit stress and greater yield loss under drought conditions. Overexpression of StPP2Ac2b accelerates senescence in response to water-deficit stress, which could also contribute to the increased sensitivity to drought. Actively photosynthesising leaves of StPP2Ac2b-OE plants exhibit elevated levels of carbohydrates and a down-regulation of the sucrose transporter StSWEET11 , suggesting a reduced sucrose export from leaves to developing tubers. This effect, combined with the hindered vegetative development, may contribute to the reduced tuber weight and yield in StPP2Ac2b-OE plants. These findings offer novel insights into the physiological functions of PP2A in potato plants and provide valuable information for enhancing potato productivity by modulating the expression of StPP2Ac2b .
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- 2023
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9. Mismatch between media coverage and research on invasive species: The case of wild boar (Sus scrofa) in Argentina.
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Ballari SA and Barrios-García MN
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- Animals, Swine, Argentina, Communication, Sus scrofa, Ecosystem, Introduced Species
- Abstract
Invasive species are a pervasive driver of global change with increasing media coverage. Media coverage and framing can influence both invasive species management and policies, as well as shed light on research needs. Using the wild boar (Sus scrofa) invasion in Argentina as a case study, we conducted a content analysis of media coverage and scientific articles. Specifically, we compared news and scientific articles based on their emphasis: ecological, economic, and health impacts and the overall perception portrayed in the news: "positive" when the articles emphasized benefits from wild boar and "negative" when focused on damage and/or loss. A literature search using Google news, Web of Science, Scielo, and Google Scholar yielded a total of 194 news articles and 37 research papers on wild boar in Argentina. More than half of the news articles focused on economic impacts of wild boar (56%) such as sport hunting, illegal hunting, and road accidents; while 27% focused on ecological impacts, and 10% on health impacts. In contrast, the majority of the scientific articles (65%) focused on ecological impacts of wild boar on native species and ecosystems; while 21% were related to health impacts and only 8.3% of scientific articles were related to economic impacts. This mismatch between media and science reveals a disconnection between social and scientific interests in wild boar and their management in Argentina, and it provides insights to research needs and prevention of management conflicts. Additionally, we found that 66.8% of news articles focused on "negative" aspects of wild boar, while 33.2% of news articles portrayed "positive" perceptions. This finding is very important because the management of invasive species such as wild boar usually requires lethal techniques, and the success of the programs depend on favorable social and political support. Good science communication is therefore key to helping scientists and managers perform more effective management actions., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Ballari, Barrios-García. 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
- 2022
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10. The protein phosphatase 2A catalytic subunit StPP2Ac2b is involved in the control of potato tuber sprouting and source-sink balance in tubers and sprouts.
- Author
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Muñiz García MN, Cortelezzi JI, and Capiati DA
- Subjects
- Protein Phosphatase 2 genetics, Protein Phosphatase 2 metabolism, Catalytic Domain, Plant Tubers metabolism, Solanum tuberosum metabolism
- Abstract
Sprouting negatively affects the quality of stored potato tubers. Understanding the molecular mechanisms that control this process is important for the development of potato varieties with desired sprouting characteristics. Serine/threonine protein phosphatase type 2A (PP2A) has been implicated in several developmental programs and stress responses in plants. PP2A comprises a catalytic (PP2Ac), a scaffolding (A), and a regulatory (B) subunit. In cultivated potato, six PP2Ac isoforms were identified, named StPP2Ac1, 2a, 2b, 3, 4, and 5. In this study we evaluated the sprouting behavior of potato tubers overexpressing the catalytic subunit 2b (StPP2Ac2b-OE). The onset of sprouting and initial sprout elongation is significantly delayed in StPP2Ac2b-OE tubers; however, sprout growth is accelerated during the late stages of development, due to a high degree of branching. StPP2Ac2b-OE tubers also exhibit a pronounced loss of apical dominance. These developmental characteristics are accompanied by changes in carbohydrate metabolism and response to gibberellic acid, and a differential balance between abscisic acid, gibberellic acid, cytokinins, and auxin. Overexpression of StPP2Ac2b alters the source-sink balance, increasing the source capacity of the tuber, and the sink strength of the sprout to support its accelerated growth., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2022
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11. The protein phosphatase 2A catalytic subunit StPP2Ac2b enhances susceptibility to Phytophthora infestans and senescence in potato.
- Author
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Muñiz García MN, Grossi C, Ulloa RM, and Capiati DA
- Subjects
- Catalytic Domain, Disease Resistance, Hormones, Plant Diseases genetics, Plants, Genetically Modified, Protein Phosphatase 2 genetics, Serine, Threonine, Phytophthora infestans physiology, Solanum tuberosum genetics
- Abstract
The serine/threonine protein phosphatases type 2A (PP2A) are involved in several physiological responses in plants, playing important roles in developmental programs, stress responses and hormone signaling. Six PP2A catalytic subunits (StPP2Ac) were identified in cultivated potato. Transgenic potato plants constitutively overexpressing the catalytic subunit StPP2Ac2b (StPP2Ac2b-OE) were developed to determine its physiological roles. The response of StPP2Ac2b-OE plants to the oomycete Phytophthora infestans, the causal agent of late blight, was evaluated. We found that overexpression of StPP2Ac2b enhances susceptibility to the pathogen. Further bioinformatics, biochemical, and molecular analyses revealed that StPP2Ac2b positively regulates developmental and pathogen-induced senescence, and that P. infestans infection promotes senescence, most likely through induction of StPP2Ac2b expression., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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12. Characterization and expression analysis of WRKY genes during leaf and corolla senescence of Petunia hybrida plants.
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Astigueta FH, Baigorria AH, García MN, Delfosse VC, González SA, Pérez de la Torre MC, Moschen S, Lia VV, Heinz RA, Fernández P, and Trupkin SA
- Abstract
Several families of transcription factors (TFs) control the progression of senescence. Many key TFs belonging to the WRKY family have been described to play crucial roles in the regulation of leaf senescence, mainly in Arabidopsis thaliana . However, little is known about senescence-associated WRKY members in floricultural species. Delay of senescence in leaves and petals of Petunia hybrida, a worldwide ornamental crop are highly appreciated traits. In this work, starting from 28 differentially expressed WRKY genes of A. thaliana during the progression of leaf senescence, we identified the orthologous in P. hybrida and explored the expression profiles of 20 PhWRKY genes during the progression of natural (age-related) leaf and corolla senescence as well as in the corollas of flowers undergoing pollination-induced senescence. Simultaneous visualization showed consistent and similar expression profiles of PhWRKYs during natural leaf and corolla senescence, although weak expression changes were observed during pollination-induced senescence. Comparable expression trends between PhWRKYs and the corresponding genes of A. thaliana were observed during leaf senescence, although more divergence was found in petals of pollinated petunia flowers. Integration of expression data with phylogenetics, conserved motif and cis -regulatory element analyses were used to establish a list of candidates that could regulate more than one senescence process. Our results suggest that several members of the WRKY family of TFs are tightly linked to the regulation of senescence in P. hybrida., Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01243-y., Competing Interests: Conflict of interestThe authors declare they have no conflict of interest., (© Prof. H.S. Srivastava Foundation for Science and Society 2022, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)
- Published
- 2022
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13. HLA-G gene editing in tumor cell lines as a novel alternative in cancer immunotherapy.
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Palma MB, Tronik-Le Roux D, Amín G, Castañeda S, Möbbs AM, Scarafia MA, La Greca A, Daouya M, Poras I, Inda AM, Moro LN, Carosella ED, García MN, and Miriuka SG
- Subjects
- CRISPR-Cas Systems, Cell Line, Tumor, HLA-G Antigens immunology, Humans, Immunotherapy methods, RNA, Guide, CRISPR-Cas Systems, Transfection, Gene Editing methods, HLA-G Antigens genetics, HLA-G Antigens metabolism
- Abstract
Cancer immunotherapies based mainly on the blockade of immune-checkpoint (IC) molecules by anti-IC antibodies offer new alternatives for treatment in oncological diseases. However, a considerable proportion of patients remain unresponsive to them. Hence, the development of novel clinical immunotherapeutic approaches and/or targets are crucial.W In this context, targeting the immune-checkpoint HLA-G/ILT2/ILT4 has caused great interest since it is abnormally expressed in several malignancies generating a tolerogenic microenvironment. Here, we used CRISPR/Cas9 gene editing to block the HLA-G expression in two tumor cell lines expressing HLA-G, including a renal cell carcinoma (RCC7) and a choriocarcinoma (JEG-3). Different sgRNA/Cas9 plasmids targeting HLA-G exon 1 and 2 were transfected in both cell lines. Downregulation of HLA-G was reached to different degrees, including complete silencing. Most importantly, HLA-G - cells triggered a higher in vitro response of immune cells with respect to HLA-G + wild type cells. Altogether, we demonstrated for the first time the HLA-G downregulation through gene editing. We propose this approach as a first step to develop novel clinical immunotherapeutic approaches in cancer., (© 2021. The Author(s).)
- Published
- 2021
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14. An Approach to Integrating Sentiment Analysis into Recommender Systems.
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Dang CN, Moreno-García MN, and Prieta F
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- Humans, Reproducibility of Results, Algorithms, Research Design
- Abstract
Recommender systems have been applied in a wide range of domains such as e-commerce, media, banking, and utilities. This kind of system provides personalized suggestions based on large amounts of data to increase user satisfaction. These suggestions help client select products, while organizations can increase the consumption of a product. In the case of social data, sentiment analysis can help gain better understanding of a user's attitudes, opinions and emotions, which is beneficial to integrate in recommender systems for achieving higher recommendation reliability. On the one hand, this information can be used to complement explicit ratings given to products by users. On the other hand, sentiment analysis of items that can be derived from online news services, blogs, social media or even from the recommender systems themselves is seen as capable of providing better recommendations to users. In this study, we present and evaluate a recommendation approach that integrates sentiment analysis into collaborative filtering methods. The recommender system proposal is based on an adaptive architecture, which includes improved techniques for feature extraction and deep learning models based on sentiment analysis. The results of the empirical study performed with two popular datasets show that sentiment-based deep learning models and collaborative filtering methods can significantly improve the recommender system's performance.
- Published
- 2021
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15. Mitochondrial Dynamics and VMP1-Related Selective Mitophagy in Experimental Acute Pancreatitis.
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Vanasco V, Ropolo A, Grasso D, Ojeda DS, García MN, Vico TA, Orquera T, Quarleri J, Alvarez S, and Vaccaro MI
- Abstract
Mitophagy and zymophagy are selective autophagy pathways early induced in acute pancreatitis that may explain the mild, auto limited, and more frequent clinical presentation of this disease. Adequate mitochondrial bioenergetics is necessary for cellular restoration mechanisms that are triggered during the mild disease. However, mitochondria and zymogen contents are direct targets of damage in acute pancreatitis. Cellular survival depends on the recovering possibility of mitochondrial function and efficient clearance of damaged mitochondria. This work aimed to analyze mitochondrial dynamics and function during selective autophagy in pancreatic acinar cells during mild experimental pancreatitis in rats. Also, using a cell model under the hyperstimulation of the G-coupled receptor for CCK (CCK-R), we aimed to investigate the mechanisms involved in these processes in the context of zymophagy. We found that during acute pancreatitis, mitochondrial O
2 consumption and ATP production significantly decreased early after induction of acute pancreatitis, with a consequent decrease in the ATP/O ratio. Mitochondrial dysfunction was accompanied by changes in mitochondrial dynamics evidenced by optic atrophy 1 (OPA-1) and dynamin-related protein 1 (DRP-1) differential expression and ultrastructural features of mitochondrial fission, mitochondrial elongation, and mitophagy during the acute phase of experimental mild pancreatitis in rats. Mitophagy was also evaluated by confocal assay after transfection with the pMITO-RFP-GFP plasmid that specifically labels autophagic degradation of mitochondria and the expression and redistribution of the ubiquitin ligase Parkin1. Moreover, we report for the first time that vacuole membrane protein-1 (VMP1) is involved and required in the mitophagy process during acute pancreatitis, observable not only by repositioning around specific mitochondrial populations, but also by detection of mitochondria in autophagosomes specifically isolated with anti-VMP1 antibodies as well. Also, VMP1 downregulation avoided mitochondrial degradation confirming that VMP1 expression is required for mitophagy during acute pancreatitis. In conclusion, we identified a novel DRP1-Parkin1-VMP1 selective autophagy pathway, which mediates the selective degradation of damaged mitochondria by mitophagy in acute pancreatitis. The understanding of the molecular mechanisms involved to restore mitochondrial function, such as mitochondrial dynamics and mitophagy, could be relevant in the development of novel therapeutic strategies in acute pancreatitis., 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 © 2021 Vanasco, Ropolo, Grasso, Ojeda, García, Vico, Orquera, Quarleri, Alvarez and Vaccaro.)- Published
- 2021
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16. Environment Monitoring of Rose Crops Greenhouse Based on Autonomous Vehicles with a WSN and Data Analysis.
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Rosero-Montalvo PD, Erazo-Chamorro VC, López-Batista VF, Moreno-García MN, and Peluffo-Ordóñez DH
- Abstract
This work presents a monitoring system for the environmental conditions of rose flower-cultivation in greenhouses. Its main objective is to improve the quality of the crops while regulating the production time. To this end, a system consisting of autonomous quadruped vehicles connected with a wireless sensor network (WSN) is developed, which supports the decision-making on type of action to be carried out in a greenhouse to maintain the appropriate environmental conditions for rose cultivation. A data analysis process was carried out, aimed at designing an in-situ intelligent system able to make proper decisions regarding the cultivation process. This process involves stages for balancing data, prototype selection, and supervised classification. The proposed system produces a significant reduction of data in the training set obtained by the WSN while reaching a high classification performance in real conditions-amounting to 90 % and 97.5%, respectively. As a remarkable outcome, it is also provided an approach to ensure correct planning and selection of routes for the autonomous vehicle through the global positioning system.
- Published
- 2020
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17. A New Look on Financial Markets Co-Movement through Cooperative Dynamics in Many-Body Physics.
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López-García MN, Sánchez-Granero MA, Trinidad-Segovia JE, Puertas AM, and Nieves FJL
- Abstract
One of the main contributions of the Capital Assets Pricing Model (CAPM) to portfolio theory was to explain the correlation between assets through its relationship with the market index. According to this approach, the market index is expected to explain the co-movement between two different stocks to a great extent. In this paper, we try to verify this hypothesis using a sample of 3.000 stocks of the USA market (attending to liquidity, capitalization, and free float criteria) by using some functions inspired by cooperative dynamics in physical particle systems. We will show that all of the co-movement among the stocks is completely explained by the market, even without considering the market beta of the stocks.
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- 2020
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18. Innovative design of a methodology for the simultaneous determination of compounds by kinetic-spectroscopy three-dimensional chemiluminescence.
- Author
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Murillo Pulgarín JA, García Bermejo LF, Sánchez García MN, and Sánchez-Ferrer Robles I
- Abstract
This report presents a novel methodology based in the quickly acquisition of full UV-vis range spectra combined with the joint determination of kinetic parameters and chemiluminescence signals. Then this technique allows obtaining three-dimensional chemiluminescence spectra profiles containing kinetic and spectroscopic information. That is especially useful for resolving mixtures of luminophors because of more analytical information for each analyte is available increasing the selectivity relative to conventional chemiluminescence methods. To accomplish this, a conventional Back-Thinned CCD detector is used and the three-dimensional chemiluminescence spectra is subsequently processed so that two-dimensional spectra with different trajectories can be obtained by dedicated software CLTotal. The potential of the proposed analytical methodology was assessed for the simultaneous determination of two polycyclic aromatic hydrocarbons. The chemiluminescent reaction between DNPO and hydrogen peroxide induced by their presence was used to record 3D spectra and the software CLTotal to subsequently construct linear variable-angle trajectories in the spectra, in order to obtain more selective 2D spectra facilitating the simultaneous determination of the analytes. The results of the statistical analysis testify to the usefulness of the proposed method for the intended purpose., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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19. Tension-type headache in the Emergency Department Diagnosis and misdiagnosis: The TEDDi study.
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García-Azorín D, Farid-Zahran M, Gutiérrez-Sánchez M, González-García MN, Guerrero AL, and Porta-Etessam J
- Subjects
- Adult, Cross-Sectional Studies, Diagnostic Errors, Emergency Service, Hospital, Female, Humans, International Classification of Diseases, Male, Middle Aged, Tension-Type Headache diagnosis
- Abstract
Headache is a common reason to visit the emergency department (ED). Tension-type headache (TTH) is the commonest headache. The diagnosis of TTH implies a mild condition, with no need for special tests. We evaluated the use of the International Classification of Headache Disorders (ICHD) criteria for TTH in the ED. We performed a cross-sectional study including all ED patients with a definite TTH diagnosis in their discharge report for 2.5 years. We evaluated whether the ICHD criteria for TTH were referenced and met. We analysed discrepancies concerning anamnesis or prior history and reclassified patients. A total of 211 out of 2132 patients fulfilled the criteria (9.9%). Only five patients fulfilled TTH criteria. Criteria A-D were referenced in 60-84% of patients and met in 16-74% of these patients. Anamnesis was discrepant in 87.5% as was prior history in 20.8%. After re-reclassification, 21 patients fulfilled the criteria for TTH (five) or probable TTH (16). In 106 patients, another headache was diagnosed, with migraine in 40 (18.9%), secondary headache in 64 (30.3%), and a life-threatening disorder in 13 (6.1%). In our sample, TTH was overdiagnosed. Only a minority of patients fulfilled the ICHD criteria. Inconsistencies in prior medical history or anamnesis were frequent.
- Published
- 2020
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20. Identification and expression analysis of NAC transcription factors potentially involved in leaf and petal senescence in Petunia hybrida.
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Trupkin SA, Astigueta FH, Baigorria AH, García MN, Delfosse VC, González SA, Pérez de la Torre MC, Moschen S, Lía VV, Fernández P, and Heinz RA
- Subjects
- Flowers genetics, Flowers physiology, Gene Expression Regulation, Plant, Petunia physiology, Phylogeny, Plant Breeding, Plant Leaves genetics, Plant Leaves physiology, Plant Proteins genetics, Plant Proteins metabolism, Pollination, Transcription Factors genetics, Up-Regulation, Petunia genetics, Transcription Factors metabolism
- Abstract
Progression of leaf senescence depends on several families of transcription factors. In Arabidopsis, the NAC family plays crucial roles in the modulation of leaf senescence; however, the mechanisms involved in this NAC-mediated regulation have not been extensively explored in agronomic species. Petunia hybrida is an ornamental plant that is commonly found worldwide. Decreasing the rate of leaf and petal senescence in P. hybrida is essential for maintaining plant quality. In this study, we examined the NAC-mediated networks involved in regulating senescence in this species. From 41 NAC genes, the expression of which changed in Arabidopsis during leaf senescence, we identified 29 putative orthologs in P. hybrida. Analysis using quantitative real-time-PCR indicated that 24 genes in P. hybrida changed their transcript levels during natural leaf senescence. Leaf-expressed genes were subsequently assessed in petals undergoing natural and pollination-induced senescence. Expression data and phylogenetic analysis were used to generate a list of 10-15 candidate genes; 7 of these were considered key regulatory candidates in senescence because of their consistent upregulation in the three senescence processes examined. Altogether, we identified common and distinct patterns of gene expression at different stages of leaf and petal development and during progression of senescence. The results obtained in this study will contribute to the understanding of NAC-mediated regulatory networks in petunia., (Copyright © 2019. Published by Elsevier B.V.)
- Published
- 2019
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21. Expression of the Arabidopsis ABF4 gene in potato increases tuber yield, improves tuber quality and enhances salt and drought tolerance.
- Author
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Muñiz García MN, Cortelezzi JI, Fumagalli M, and Capiati DA
- Subjects
- Arabidopsis Proteins metabolism, Basic-Leucine Zipper Transcription Factors metabolism, Chlorophyll metabolism, Electron Transport drug effects, Oxidation-Reduction, Photosynthesis drug effects, Plant Stomata drug effects, Plant Stomata genetics, Plant Stomata physiology, Plant Transpiration drug effects, Plant Transpiration genetics, Plant Tubers drug effects, Plants, Genetically Modified, Proline metabolism, Salt Tolerance drug effects, Sodium Chloride pharmacology, Solanum tuberosum drug effects, Water, Arabidopsis genetics, Arabidopsis Proteins genetics, Basic-Leucine Zipper Transcription Factors genetics, Droughts, Gene Expression Regulation, Plant drug effects, Plant Tubers genetics, Plant Tubers physiology, Salt Tolerance genetics, Solanum tuberosum genetics
- Abstract
Key Message: In this study we show that expression of the Arabidopsis ABF4 gene in potato increases tuber yield under normal and abiotic stress conditions, improves storage capability and processing quality of the tubers, and enhances salt and drought tolerance. Potato is the third most important food crop in the world. Potato plants are susceptible to salinity and drought, which negatively affect crop yield, tuber quality and market value. The development of new varieties with higher yields and increased tolerance to adverse environmental conditions is a main objective in potato breeding. In addition, tubers suffer from undesirable sprouting during storage that leads to major quality losses; therefore, the control of tuber sprouting is of considerable economic importance. ABF (ABRE-binding factor) proteins are bZIP transcription factors that regulate abscisic acid signaling during abiotic stress. ABF proteins also play an important role in the tuberization induction. We developed transgenic potato plants constitutively expressing the Arabidopsis ABF4 gene (35S::ABF4). In this study, we evaluated the performance of 35S::ABF4 plants grown in soil, determining different parameters related to tuber yield, tuber quality (carbohydrates content and sprouting behavior) and tolerance to salt and drought stress. Besides enhancing salt stress and drought tolerance, constitutive expression of ABF4 increases tuber yield under normal and stress conditions, enhances storage capability and improves the processing quality of the tubers.
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- 2018
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22. The plasma membrane H+-ATPase gene family in Solanum tuberosum L. Role of PHA1 in tuberization.
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Stritzler M, Muñiz García MN, Schlesinger M, Cortelezzi JI, and Capiati DA
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- Cell Membrane metabolism, Multigene Family genetics, Phylogeny, Plant Proteins metabolism, Plant Tubers metabolism, Plants, Genetically Modified genetics, Plants, Genetically Modified growth & development, Sequence Analysis, DNA, Solanum tuberosum growth & development, Plant Proteins genetics, Plant Tubers genetics, Solanum tuberosum genetics, Transcriptome
- Abstract
This study presents the characterization of the plasma membrane (PM) H+-ATPases in potato, focusing on their role in stolon and tuber development. Seven PM H+-ATPase genes were identified in the Solanum tuberosum genome, designated PHA1-PHA7. PHA genes show distinct expression patterns in different plant tissues and under different stress treatments. Application of PM H+-ATPase inhibitors arrests stolon growth, promotes tuber induction, and reduces tuber size, indicating that PM H+-ATPases are involved in tuberization, acting at different stages of the process. Transgenic potato plants overexpressing PHA1 were generated (PHA1-OE). At early developmental stages, PHA1-OE stolons elongate faster and show longer epidermal cells than wild-type stolons; this accelerated growth is accompanied by higher cell wall invertase activity, lower starch content, and higher expression of the sucrose-H+ symporter gene StSUT1. PHA1-OE stolons display an increased branching phenotype and develop larger tubers. PHA1-OE plants are taller and also present a highly branched phenotype. These results reveal a prominent role for PHA1 in plant growth and development. Regarding tuberization, PHA1 promotes stolon elongation at early stages, and tuber growth later on. PHA1 is involved in the sucrose-starch metabolism in stolons, possibly providing the driving force for sugar transporters to maintain the apoplastic sucrose transport during elongation., (© The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.)
- Published
- 2017
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23. Multiclassifier Systems for Predicting Neurological Outcome of Patients with Severe Trauma and Polytrauma in Intensive Care Units.
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González-Robledo J, Martín-González F, Sánchez-Barba M, Sánchez-Hernández F, and Moreno-García MN
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- Brain Injuries, Traumatic, Humans, Intensive Care Units, Sensitivity and Specificity, Multiple Trauma
- Abstract
This paper presents an ensemble based classification proposal for predicting neurological outcome of severely traumatized patients. The study comprises both the whole group of patients and a subgroup containing those patients suffering traumatic brain injury (TBI). Data was gathered from patients hospitalized in the Intensive Care Unit (ICU) of the University Hospital in Salamanca. Predictive models were induced from both epidemiologic and clinical variables taken at the emergency room and along the stay in the ICU. The large number of variables leads to a low accuracy in the classifiers even when feature selection methods are used. In addition, the presence of a much larger number of instances of one of the classes in the subgroup of TBI patients produces a significantly lesser precision for the minority class. Usual ways of dealing with the last problem is to use undersampling and oversampling strategies, which can lead to the loss of valuable data and overfitting problems respectively. Our proposal for dealing with these problems is based in the use of ensemble multiclassifiers as well as in the use of an ensemble playing the role of base classifier in multiclassifiers. The proposed strategy gave the best values of the selected quality measures (accuracy, precision, sensitivity, specificity, F-measure and area under the Receiver Operator Characteristic curve) as well as the closest values of precision for the two classes under study in the case of the classification from imbalanced data.
- Published
- 2017
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24. Porcine circovirus type 2 protective epitope densely carried by chimeric papaya ringspot virus-like particles expressed in Escherichia coli as a cost-effective vaccine manufacture alternative.
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Aguilera BE, Chávez-Calvillo G, Elizondo-Quiroga D, Jimenez-García MN, Carrillo-Tripp M, Silva-Rosales L, Hernández-Gutiérrez R, and Gutiérrez-Ortega A
- Subjects
- Animals, Mice, Porcine Postweaning Multisystemic Wasting Syndrome immunology, Porcine Postweaning Multisystemic Wasting Syndrome prevention & control, Swine, Capsid Proteins biosynthesis, Capsid Proteins genetics, Capsid Proteins immunology, Circovirus genetics, Circovirus immunology, Epitopes biosynthesis, Epitopes genetics, Epitopes immunology, Gene Expression, Plant Viruses genetics, Plant Viruses immunology, Plant Viruses metabolism, Viral Vaccines biosynthesis, Viral Vaccines genetics, Viral Vaccines immunology
- Abstract
Porcine circovirus type 2 (PCV2) still represents a major problem to the swine industry worldwide, causing high mortality rates in infected animals. Virus-like particles (VLPs) have gained attention for vaccine development, serving both as scaffolds for epitope expression and immune response enhancers. The commercial subunit vaccines against PCV2 consist of VLPs formed by the self-assembly of PCV2 capsid protein (CP) expressed in the baculovirus vector system. In this work, a PCV2 protective epitope was inserted into three different regions of papaya ringspot virus (PRSV) CP, namely, the N- and C-termini and a predicted antigenic region located near the N-terminus. Wild-type and chimeric CPs were modeled in silico, expressed in Escherichia coli, purified, and visualized by transmission electron microscopy. This is the first report that shows the formation of chimeric VLPs using PRSV as epitope-presentation scaffold. Moreover, it was found that PCV2 epitope localization strongly influences VLP length. Also, the estimated yields of the chimeric VLPs at a small-scale level ranged between 65 and 80 mg/L of culture medium. Finally, the three chimeric VLPs induced high levels of immunoglobulin G against the PCV2 epitope in immunized BALB/c mice, suggesting that these chimeric VLPs can be used for swine immunoprophylaxis against PCV2., (© 2016 International Union of Biochemistry and Molecular Biology, Inc.)
- Published
- 2017
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25. The protein phosphatase 2A catalytic subunit StPP2Ac2b acts as a positive regulator of tuberization induction in Solanum tuberosum L.
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Muñiz García MN, Muro MC, Mazzocchi LC, País SM, Stritzler M, Schlesinger M, and Capiati DA
- Subjects
- Abscisic Acid metabolism, Abscisic Acid pharmacology, Gene Expression Regulation, Plant drug effects, Gibberellins metabolism, Gibberellins pharmacology, Models, Biological, Plant Proteins genetics, Plants, Genetically Modified, Signal Transduction drug effects, Solanum tuberosum drug effects, Solanum tuberosum genetics, Solanum tuberosum growth & development, Time Factors, Up-Regulation drug effects, Up-Regulation genetics, Catalytic Domain, Plant Proteins chemistry, Plant Proteins metabolism, Plant Tubers metabolism, Protein Phosphatase 2 chemistry, Protein Phosphatase 2 metabolism, Solanum tuberosum enzymology
- Abstract
Key Message: This study provides the first genetic evidence for the role of PP2A in tuberization, demonstrating that the catalytic subunit StPP2Ac2b positively modulates tuber induction, and that its function is related to the regulation of gibberellic acid metabolism. The results contribute to a better understanding of the molecular mechanism controlling tuberization induction, which remains largely unknown. The serine/threonine protein phosphatases type 2A (PP2A) are implicated in several physiological processes in plants, playing important roles in hormone responses. In cultivated potato (Solanum tuberosum), six PP2A catalytic subunits (StPP2Ac) were identified. The PP2Ac of the subfamily I (StPP2Ac1, 2a and 2b) were suggested to be involved in the tuberization signaling in leaves, where the environmental and hormonal signals are perceived and integrated. The aim of this study was to investigate the role of PP2A in the tuberization induction in stolons. We selected one of the catalytic subunits of the subfamily I, StPP2Ac2b, to develop transgenic plants overexpressing this gene (StPP2Ac2b-OE). Stolons from StPP2Ac2b-OE plants show higher tuber induction rates in vitro, as compared to wild type stolons, with no differences in the number of tubers obtained at the end of the process. This effect is accompanied by higher expression levels of the gibberellic acid (GA) catabolic enzyme StGA2ox1. GA up-regulates StPP2Ac2b expression in stolons, possibly as part of the feedback system by which the hormone regulates its own level. Sucrose, a tuber-promoting factor in vitro, increases StPP2Ac2b expression. We conclude that StPP2Ac2b acts in stolons as a positive regulator tuber induction, integrating different tuberization-related signals mainly though the modulation of GA metabolism.
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- 2017
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26. StCDPK3 Phosphorylates In Vitro Two Transcription Factors Involved in GA and ABA Signaling in Potato: StRSG1 and StABF1.
- Author
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Grandellis C, Fantino E, Muñiz García MN, Bialer MG, Santin F, Capiati DA, and Ulloa RM
- Subjects
- Abscisic Acid metabolism, Arabidopsis genetics, Arabidopsis Proteins genetics, Basic-Leucine Zipper Transcription Factors genetics, Calcium Signaling genetics, Focal Adhesion Kinase 2 genetics, Gene Expression Regulation, Plant, Gibberellins metabolism, Phosphorylation, Recombinant Proteins metabolism, Repressor Proteins genetics, Serine, Solanum tuberosum growth & development, Solanum tuberosum metabolism, Nicotiana genetics, Transcription Factors metabolism, Focal Adhesion Kinase 2 metabolism, Plant Proteins genetics, Recombinant Proteins genetics, Solanum tuberosum genetics, Transcription Factors genetics
- Abstract
Calcium-dependent protein kinases, CDPKs, decode calcium (Ca2+) transients and initiate downstream responses in plants. In order to understand how CDPKs affect plant physiology, their specific target proteins must be identified. In tobacco, the bZIP transcription factor Repression of Shoot Growth (NtRSG) that modulates gibberellin (GA) content is a specific target of NtCDPK1. StCDPK3 from potato is homologous (88% identical) to NtCDPK1 even in its N-terminal variable domain. In this work, we observe that NtRSG is also phosphorylated by StCDPK3. The potato RSG family of transcription factors is composed of three members that share similar features. The closest homologue to NtRSG, which was named StRSG1, was amplified and sequenced. qRT-PCR data indicate that StRSG1 is mainly expressed in petioles, stems, lateral buds, and roots. In addition, GA treatment affected StRSG1 expression. StCDPK3 transcripts were detected in leaves, petioles, stolons, roots, and dormant tubers, and transcript levels were modified in response to GA. The recombinant StRSG1-GST protein was produced and tested as a substrate for StCDPK3 and StCDPK1. 6xHisStCDPK3 was able to phosphorylate the potato StRSG1 in a Ca2+-dependent way, while 6xHisStCDPK1 could not. StCDPK3 also interacts and phosphorylates the transcription factor StABF1 (ABRE binding factor 1) involved in ABA signaling, as shown by EMSA and phosphorylation assays. StABF1 transcripts were mainly detected in roots, stems, and stolons. Our data suggest that StCDPK3 could be involved in the cross-talk between ABA and GA signaling at the onset of tuber development., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2016
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27. Reply to Prediction of Non-invasive Mechanical Ventilation Response. Moving from Art to Science.
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Martín-González F, González-Robledo J, Sánchez F, and Moreno-García MN
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- Humans, Patient Selection, Pulmonary Disease, Chronic Obstructive therapy, Art, Respiration, Artificial, Science
- Published
- 2016
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28. Success/Failure Prediction of Noninvasive Mechanical Ventilation in Intensive Care Units. Using Multiclassifiers and Feature Selection Methods.
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Martín-González F, González-Robledo J, Sánchez-Hernández F, and Moreno-García MN
- Subjects
- Data Mining, Databases as Topic, Decision Trees, Humans, Treatment Outcome, Algorithms, Intensive Care Units, Respiration, Artificial
- Abstract
Objectives: This paper addresses the problem of decision-making in relation to the administration of noninvasive mechanical ventilation (NIMV) in intensive care units., Methods: Data mining methods were employed to find out the factors influencing the success/failure of NIMV and to predict its results in future patients. These artificial intelligence-based methods have not been applied in this field in spite of the good results obtained in other medical areas., Results: Feature selection methods provided the most influential variables in the success/failure of NIMV, such as NIMV hours, PaCO2 at the start, PaO2 / FiO2 ratio at the start, hematocrit at the start or PaO2 / FiO2 ratio after two hours. These methods were also used in the preprocessing step with the aim of improving the results of the classifiers. The algorithms provided the best results when the dataset used as input was the one containing the attributes selected with the CFS method., Conclusions: Data mining methods can be successfully applied to determine the most influential factors in the success/failure of NIMV and also to predict NIMV results in future patients. The results provided by classifiers can be improved by preprocessing the data with feature selection techniques.
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- 2016
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29. Effectiveness and predictors of failure of noninvasive mechanical ventilation in acute respiratory failure.
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Martín-González F, González-Robledo J, Sánchez-Hernández F, Moreno-García MN, and Barreda-Mellado I
- Subjects
- Acute Disease, Humans, Positive-Pressure Respiration, Respiratory Insufficiency etiology, Retrospective Studies, Noninvasive Ventilation, Respiration, Artificial, Respiratory Insufficiency therapy
- Abstract
Objective: To assess the effectiveness and identify predictors of failure of noninvasive ventilation., Design: A retrospective, longitudinal descriptive study was made., Setting: Adult patients with acute respiratory failure., Patients: A total of 410 consecutive patients with noninvasive ventilation treated in an Intensive Care Unit of a tertiary university hospital from 2006 to 2011., Procedures: Noninvasive ventilation., Main Variables of Interest: Demographic variables and clinical and laboratory test parameters at the start and two hours after the start of noninvasive ventilation. Evolution during admission to the Unit and until hospital discharge., Results: The failure rate was 50%, with an overall mortality rate of 33%. A total of 156 patients had hypoxemic respiratory failure, 87 postextubation respiratory failure, 78 exacerbation of chronic obstructive pulmonary disease, 61 hypercapnic respiratory failure without chronic obstructive pulmonary disease, and 28 had acute pulmonary edema. The failure rates were 74%, 54%, 27%, 31% and 21%, respectively. The etiology of respiratory failure, serum bilirubin at the start, APACHEII score, radiological findings, the need for sedation to tolerate noninvasive ventilation, changes in level of consciousness, PaO2/FIO2 ratio, respiratory rate and heart rate from the start and two hours after the start of noninvasive ventilation were independently associated to failure., Conclusions: The effectiveness of noninvasive ventilation varies according to the etiology of respiratory failure. Its use in hypoxemic respiratory failure and postextubation respiratory failure should be assessed individually. Predictors of failure could be useful to prevent delayed intubation., (Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.)
- Published
- 2016
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30. Pervasive effects of a dominant foliar endophytic fungus on host genetic and phenotypic expression in a tropical tree.
- Author
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Mejía LC, Herre EA, Sparks JP, Winter K, García MN, Van Bael SA, Stitt J, Shi Z, Zhang Y, Guiltinan MJ, and Maximova SN
- Abstract
It is increasingly recognized that macro-organisms (corals, insects, plants, vertebrates) consist of both host tissues and multiple microbial symbionts that play essential roles in their host's ecological and evolutionary success. Consequently, identifying benefits and costs of symbioses, as well as mechanisms underlying them are research priorities. All plants surveyed under natural conditions harbor foliar endophytic fungi (FEF) in their leaf tissues, often at high densities. Despite producing no visible effects on their hosts, experiments have nonetheless shown that FEF reduce pathogen and herbivore damage. Here, combining results from three genomic, and two physiological experiments, we demonstrate pervasive genetic and phenotypic effects of the apparently asymptomatic endophytes on their hosts. Specifically, inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant FEF species in healthy T. cacao, induces consistent changes in the expression of hundreds of host genes, including many with known defensive functions. Further, E+ plants exhibited increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes. These phenotypic changes observed in E+ plants correspond to changes in expression of specific functional genes in related pathways. Moreover, a cacao gene (Tc00g04254) highly up-regulated by C. tropicale also confers resistance to pathogen damage in the absence of endophytes or their products in host tissues. Thus, the benefits of increased pathogen resistance in E+ plants are derived in part from up-regulation of intrinsic host defense responses, and appear to be offset by potential costs including reduced photosynthesis, altered host nitrogen metabolism, and endophyte heterotrophy of host tissues. Similar effects are likely in most plant-endophyte interactions, and should be recognized in the design and interpretation of genetic and phenotypic studies of plants.
- Published
- 2014
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31. Heterologous expression of Arabidopsis ABF4 gene in potato enhances tuberization through ABA-GA crosstalk regulation.
- Author
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Muñiz García MN, Stritzler M, and Capiati DA
- Subjects
- Abscisic Acid metabolism, Arabidopsis Proteins metabolism, Basic-Leucine Zipper Transcription Factors metabolism, DNA-Binding Proteins metabolism, Gibberellins metabolism, Plants, Genetically Modified physiology, Receptor Cross-Talk, Transcription Factors metabolism, Arabidopsis genetics, Arabidopsis Proteins genetics, Basic-Leucine Zipper Transcription Factors genetics, DNA-Binding Proteins genetics, Plant Tubers growth & development, Solanum tuberosum physiology, Transcription Factors genetics
- Abstract
Potato (Solanum tuberosum L.) tuberization is regulated by many signals, such as abscisic acid (ABA), sucrose and gibberellic acid (GA). ABA and sucrose are positive modulators, while GA is an inhibitor of the process. ABF (ABRE-binding factor) proteins are transcription factors involved in ABA and stress signaling. Previously, we reported that S. tuberosum StABF1 could mediate the ABA effects on tuberization. The aim of the present study was to evaluate the potential use of ABF genes to enhance tuberization and to determine the molecular mechanism involved. For this purpose, transgenic potato plants expressing the Arabidopsis ABF4 or ABF2 genes were generated, and their tuberization capacity and response to tuberization-related signals were analyzed in vitro. The results indicate that both ABF4 and ABF2 proteins positively regulate potato tuber induction; however, only ABF4 expression significantly increases the number and weight of the tubers obtained, without stunting growth. ABF4 and ABF2 transgenic plants exhibit ABA hypersensitivity during tuberization, accompanied by a GA-deficient phenotype. ABF4 expression triggers a significant rise in ABA levels in stolons under tuber-inducing conditions as compared with wild-type plants and a transcriptional deregulation of GA metabolism genes. Our results demonstrate that Arabidopsis ABF4 functions in potato ABA-GA signaling crosstalk during tuberization by regulating the expression of ABA- and GA-metabolism genes. ABF4 gene might be a potential tool to increase tuber production, since its heterologous expression in potato enhances tuber induction without affecting plant growth.
- Published
- 2014
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32. Mesenchymal stromal cells derived from the bone marrow of acute lymphoblastic leukemia patients show altered BMP4 production: correlations with the course of disease.
- Author
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Vicente López Á, Vázquez García MN, Melen GJ, Entrena Martínez A, Cubillo Moreno I, García-Castro J, Orellana MR, and González AG
- Subjects
- Adolescent, Antigens, CD34 metabolism, Cell Differentiation, Cell Line, Tumor, Cell Proliferation, Cell Survival, Child, Child, Preschool, Coculture Techniques, Disease Progression, Female, Hematopoietic Stem Cells cytology, Hematopoietic Stem Cells metabolism, Humans, Immunophenotyping, Infant, Male, Mesenchymal Stem Cells cytology, Neoplasm Staging, Neoplastic Stem Cells metabolism, Phenotype, Precursor Cell Lymphoblastic Leukemia-Lymphoma genetics, Precursor Cell Lymphoblastic Leukemia-Lymphoma pathology, Signal Transduction, Bone Morphogenetic Protein 4 biosynthesis, Mesenchymal Stem Cells metabolism, Precursor Cell Lymphoblastic Leukemia-Lymphoma metabolism
- Abstract
The relevance of tumor microenvironment for the development and progression of tumor cells in hematological malignancies has been extensively reported. Identification of factors involved in the information exchange between the malignant cells and the bone marrow mesenchymal stem cells (BM-MSCs) and the knowledge on their functioning may provide important information to eliminate leukemic cells from protective BM niches. We evaluated changes in BM-MSCs obtained from children with acute lymphoblastic leukemia (ALL) at different times in the course of disease. Whereas ALL-MSCs did not exhibit phenotypic changes compared to BM-derived MSCs isolated from healthy donors, they exhibited increased adipogenic capacity. In addition, the viability of healthy CD34+ hematopoietic progenitors was significantly reduced when co-cultured with ALL-MSCs. ALL-MSCs grow less efficiently, although gradually recover normal growth with treatment. Accordingly, proliferation is particularly low in MSCs obtained at diagnosis and in the first days of treatment (+15 days), recovering to control levels after 35 days of treatment. Correlating these results with bone morphogenetic protein 4 (BMP4) production, a molecule demonstrated to affect MSC biology, we found higher production of BMP4 in ALL-MSCs derived from patients over the course of disease but not in those free of leukemia. However, no significant differences in the expression of different members of the BMP4 signaling pathway were observed. Furthermore, an inverse correlation between high levels of BMP4 production in the cultures and MSC proliferation was found, as observed in MSCs derived from patients at diagnosis that produce high BMP4 levels. In addition, co-culturing ALL-MSC with the REH leukemia cell line, but not CD34+ hematopoietic progenitors, powerfully enhanced BMP4 production, suggesting an intimate crosstalk among ALL-MSCs isolated from BM colonized by ALL cells that presumably also occurs in situ conditions. Our data may support the participation of BMP4 in BM niche, but the mechanism remains to be elucidated.
- Published
- 2014
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33. Comparative proteomic analysis of thiol proteins in the liver after oxidative stress induced by diethylnitrosamine.
- Author
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Aparicio-Bautista DI, Pérez-Carreón JI, Gutiérrez-Nájera N, Reyes-Grajeda JP, Arellanes-Robledo J, Vásquez-Garzón VR, Jiménez-García MN, and Villa-Treviño S
- Subjects
- Alkylating Agents pharmacology, Animals, Antioxidants metabolism, Diethylnitrosamine pharmacology, Liver pathology, Male, Necrosis chemically induced, Necrosis metabolism, Necrosis pathology, Oxidoreductases metabolism, Proteomics, Rats, Rats, Inbred F344, Sulfhydryl Compounds metabolism, Alkylating Agents adverse effects, Diethylnitrosamine adverse effects, Liver metabolism, Oxidative Stress drug effects, Proteome metabolism
- Abstract
Conversion of protein -SH groups to disulfides is an early event during protein oxidation, which has prompted great interest in the study of thiol proteins. Chemical carcinogenesis is strongly associated with the formation of reactive oxygen species (ROS). The goal of this study was to detect thiol proteins that are sensitive to ROS generated during diethylnitrosamine (DEN) metabolism in the rat liver. DEN has been widely used to induce experimental hepatocellular carcinoma. We used modified redox-differential gel electrophoresis (redox-DIGE method) and mass spectrometry MALDI-TOF/TOF to identify differential oxidation protein profiles associated with carcinogen exposure. Our analysis revealed a time-dependent increase in the number of oxidized thiol proteins after carcinogen treatment; some of these proteins have antioxidant activity, including thioredoxin, peroxirredoxin 2, peroxiredoxin 6 and glutathione S-transferase alpha-3. According to functional classifications, the identified proteins in our study included chaperones, oxidoreductases, activity isomerases, hydrolases and other protein-binding partners. This study demonstrates that oxidative stress generated by DEN tends to increase gradually through DEN metabolism, causes time-dependent necrosis in the liver and has an oxidative effect on thiol proteins, thereby increasing the number of oxidized thiol proteins. Furthermore, these events occurred during the hepatocarcinogenesis initiation period., (© 2013.)
- Published
- 2013
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34. Study of DNA synthesis and mitotic activity of hepatocytes and its relation to angiogenesis in hepatectomised tumour bearing mice.
- Author
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Andrini LB, García MN, Inda AM, and Errecalde AL
- Subjects
- Animals, Circadian Rhythm, Hepatocytes pathology, Liver Neoplasms pathology, Liver Neoplasms physiopathology, Male, Mice, Neovascularization, Pathologic pathology, Neovascularization, Pathologic physiopathology, Vascular Endothelial Growth Factor A metabolism, DNA biosynthesis, Hepatectomy, Hepatocytes metabolism, Liver Neoplasms blood supply, Liver Neoplasms surgery, Mitosis, Neovascularization, Pathologic metabolism
- Abstract
Partial hepatectomy (PH) alters serum concentrations of substances involved in cellular proliferation, leading to the compensatory liver hyperplasia. Furthermore, angiogenesis is mainly stimulated by vascular endothelial growth factor (VEGF) and is a fundamental requirement either in liver regeneration or in tumours growth. This study looks at the expression of VEGF, DNA synthesis (DNAs) and mitotic activity (MA) in hepatectomised (H) and hepatectomised-tumour bearing (HTB) mice throughout a 24 h period. Adult male mice were sacrificed every 4 h from 26 to 50 h post-hepatectomy. H mice show a circadian rhythm in VEGF expression with a maximum value of 2.6 ± 0.1 at 08/46 h of day/hours posthepatectomy (HD/HPH); in DNAs, the maximum value was 3.4 ± 0.3 at 16/30 (HD/HPH) and in MA it was 2.3 ± 0.01 at 12/50 (HD/HPH). In HTB animals the peak of VEGF expression appears at 16/30 (HD/HPH) with a maximum value of 3.7 ± 0.1, the peak of DNAs was at 00/38 (HD/HPH) with a value of 4.6 ± 0.3 and the maximum value of MA of 08/46 (HD/HPH) with a value of 3.01 ± 0.3. We can conclude that the presence of the tumour induces modifications in the intensity and the temporal distribution of the circadian curves of VEGF expression, DNAs and MA of hepatectomised animals., (© 2013 International Federation for Cell Biology.)
- Published
- 2013
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35. The chemopreventive capacity of quercetin to induce programmed cell death in hepatocarcinogenesis.
- Author
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Vásquez-Garzón VR, Macias-Pérez JR, Jiménez-García MN, Villegas V, Fattel-Fazenta S, and Villa-Treviño S
- Subjects
- Animals, Anticarcinogenic Agents pharmacology, Antineoplastic Agents pharmacology, Carcinogenesis drug effects, Caspases metabolism, Chemoprevention methods, Liver chemistry, Liver drug effects, Liver pathology, Liver Neoplasms, Experimental chemistry, Liver Neoplasms, Experimental metabolism, Male, Oxidative Stress drug effects, Precancerous Conditions chemistry, Precancerous Conditions metabolism, Precancerous Conditions pathology, Rats, Rats, Inbred F344, Apoptosis drug effects, Liver Neoplasms, Experimental pathology, Liver Neoplasms, Experimental prevention & control, Precancerous Conditions drug therapy, Quercetin pharmacology
- Abstract
In this study of chemoprevention in the rat modified resistant hepatocyte model, preneoplastic cells were diminished by >60% with quercetin pretreatment compared with those rats treated with N-Diethylnitrosamine (DEN) to induce liver cancer. This decrease occurred associated with an abolished DEN-induced lipid peroxidation as well as activation of caspase 9 and increased caspase 3, as determined by increased expression of cleaved caspase 3 and 9, but not cleaved caspase 8 and increased fragmentation of Poly (ADP-ribose) polymerase (PARP) inducing apoptosis of presumed genetically injured cells, when quercetin was administered before the initiation agent.
- Published
- 2013
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36. Pesticide-induced decrease in rat testicular steroidogenesis is differentially prevented by lipoate and tocopherol.
- Author
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Astiz M, Hurtado de Catalfo GE, García MN, Galletti SM, Errecalde AL, de Alaniz MJ, and Marra CA
- Subjects
- Animals, Gonadal Steroid Hormones blood, Male, Oxidative Stress drug effects, Rats, Rats, Wistar, Reactive Oxygen Species metabolism, Antioxidants pharmacology, Environmental Pollutants toxicity, Pesticides toxicity, Testis drug effects, Thioctic Acid pharmacology, Tocopherols pharmacology
- Abstract
We have previously demonstrated that the sub-chronic administration of low doses of Toc or α-Toc, glyphosate and zineb to rats (i.p. 1/250 LD50, three times a week for 5 weeks) provoked severe oxidative stress (OS) in testicles. These effects were also reflected in plasma. Lipoic acid (LA) and α-tocopherol are considered as antioxidants due to their ability to neutralize reactive oxygenated species (ROS) and reset endogenous antioxidant levels. To investigate the possible protective effect on reproductive function, LA and Toc (i.p. 25, 50 and 100mg/kg) were administered simultaneously with the pesticide mixture (PM) for 5 weeks. Both drugs prevented OS and the damage to proteins and lipids caused by PM in a dose-dependent manner. The PM-induced increase levels of prostaglandins E2 and F2α was completely restored by LA but not by Toc. Similarly, only LA was able to restore the inhibition of testosterone production, the decrease of 3β- and 17β-hydroxysteroid dehydrogenases activities, and the elevation of gonatropins (FSH and LH) levels produced by PM. Furthermore, LA was more efficient than Toc in normalizing the histological alterations produced by PM administration, suggesting that pesticides act though other mechanisms that generate oxidative stress. In our experimental model LA displayed a higher protective role against pesticide-induced damage than that observed by Toc administration. Our results suggest that LA administration is a promising therapeutic strategy for coping with disorders suspected to be caused by OS generators - such as pesticides - in male reproductive system., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
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37. Characterization of StABF1, a stress-responsive bZIP transcription factor from Solanum tuberosum L. that is phosphorylated by StCDPK2 in vitro.
- Author
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Muñiz García MN, Giammaria V, Grandellis C, Téllez-Iñón MT, Ulloa RM, and Capiati DA
- Subjects
- Abscisic Acid metabolism, Arabidopsis genetics, Arabidopsis metabolism, Gene Expression Regulation, Plant, Phosphorylation, Plant Proteins metabolism, Plant Tubers growth & development, Stress, Physiological physiology, Basic-Leucine Zipper Transcription Factors genetics, Basic-Leucine Zipper Transcription Factors metabolism, Solanum genetics, Solanum metabolism
- Abstract
ABF/AREB bZIP transcription factors mediate plant abiotic stress responses by regulating the expression of stress-related genes. These proteins bind to the abscisic acid (ABA)-responsive element (ABRE), which is the major cis-acting regulatory sequence in ABA-dependent gene expression. In an effort to understand the molecular mechanisms of abiotic stress resistance in cultivated potato (Solanum tuberosum L.), we have cloned and characterized an ABF/AREB-like transcription factor from potato, named StABF1. The predicted protein shares 45-57% identity with A. thaliana ABFs proteins and 96% identity with the S. lycopersicum SlAREB1 and presents all of the distinctive features of ABF/AREB transcription factors. Furthermore, StABF1 is able to bind to the ABRE in vitro. StABF1 gene is induced in response to ABA, drought, salt stress and cold, suggesting that it might be a key regulator of ABA-dependent stress signaling pathways in cultivated potato. StABF1 is phosphorylated in response to ABA and salt stress in a calcium-dependent manner, and we have identified a potato CDPK isoform (StCDPK2) that phosphorylates StABF1 in vitro. Interestingly, StABF1 expression is increased during tuber development and by tuber-inducing conditions (high sucrose/nitrogen ratio) in leaves. We also found that StABF1 calcium-dependent phosphorylation is stimulated by tuber-inducing conditions and inhibited by gibberellic acid, which inhibits tuberization.
- Published
- 2012
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38. Flow injection chemiluminescence determination of vitamin B12 using on-line UV-persulfate photooxidation and charge coupled device detection.
- Author
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Murillo Pulgarín JA, García Bermejo LF, and Sánchez García MN
- Subjects
- Luminescence, Oxidation-Reduction, Photochemistry, Ultraviolet Rays, Flow Injection Analysis methods, Vitamin B 12 analysis
- Abstract
A sensitive chemiluminescence method for vitamin B(12) using a charge-coupled device (CCD) photodetector combined with on-line UV-persulfate oxidation in a simple continuous flow system has been developed. The principle for the determination of vitamin B(12) is based on the enhancive effect of cobalt (II) on the chemiluminescence reaction between luminol and percarbonate in alkaline medium. In addition, percarbonate has been investigated and proposed as a powerful source of hydrogen peroxide as oxidant agent in this chemiluminescence reaction. The digestion of vitamin B(12) to release the cobalt (II) is reached by UV irradiation treatment in a persulfate medium. The CCD detector, directly connected to the flow cell, is used with the continuous flow manifold to obtain the full spectral characteristics of cobalt (II) catalyzed luminol-percarbonate reaction. The vitamin B(12) oxidation process and chemical conditions for the chemiluminescence reaction were investigated and optimized. The increment of the emission intensity was proportional to the concentration of vitamin B(12) , giving a second-order calibration graph over the cobalt (II) concentration range from 10 to 5000 μg L(-1)(r(2) = 0.9985) with a detection limit of 9.3 μg L(-1). The proposed method was applied to the determination of vitamin B(12) in different kinds of pharmaceuticals., (Copyright © 2011 John Wiley & Sons, Ltd.)
- Published
- 2011
- Full Text
- View/download PDF
39. Low doses of bone morphogenetic protein 4 increase the survival of human adipose-derived stem cells maintaining their stemness and multipotency.
- Author
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Vicente López MA, Vázquez García MN, Entrena A, Olmedillas Lopez S, García-Arranz M, García-Olmo D, and Zapata A
- Subjects
- Adult, Bone Morphogenetic Protein 2 metabolism, Bone Morphogenetic Protein 4 biosynthesis, Cell Proliferation drug effects, Cell Survival drug effects, Cells, Cultured, Culture Media, Serum-Free pharmacology, Female, Gene Expression Regulation drug effects, Humans, Multipotent Stem Cells metabolism, Osteogenesis drug effects, Osteogenesis genetics, Phenotype, Signal Transduction drug effects, Transcription Factors metabolism, Adipose Tissue cytology, Bone Morphogenetic Protein 4 pharmacology, Multipotent Stem Cells cytology, Multipotent Stem Cells drug effects
- Abstract
Mesenchymal stem cells (MSCs) have emerged as important tools for cell therapy; therefore, identification of factors capable of governing their ex vivo expansion become essential. In this study we demonstrate that human adipose-derived stem cells (ASCs) express all components of the bone morphogenetic protein (BMP)/BMP receptor signaling pathway and respond to BMP4 inducing upregulated expression of its specific target genes Id1-Id4. Moreover, ASCs grown in a medium reduced in serum produce endogenous BMP4 that could affect autocrinely ASC growth. On the contrary, dorsomorphin, an inhibitor of BMP signaling pathway, decreases cell numbers yielded from ASC cultures in correlation with increased apoptosis and decreased cycling cells. Therefore, BMP4 emerges as a possible factor for ex vivo expanding human ASCs. Our results demonstrate that, as other morphogens, BMP4 effects on human MSCs are dose dependent. High doses significantly increased apoptosis and drastically reduced cell proliferation, whereas low doses of BMP4 (0.01-0.1 ng/mL) significantly increase culture cell content, reduce the number of apoptotic cells, and increase that of cycling cells. Further, treatment of human ASCs with low doses of BMP4 does not modify expression of Nanog and Oct4, two transcription factors involved in self-renewal and pluripotency of stem cells or avoid their osteogenic or osteoblastic differentiation capacities when cultured in adequate inducing media, as shown by the induction of specific gene expression (CEBP, PPARγ, and RUNX2). Our results therefore support BMP4 as a promising factor for expanding human adipose tissue-derived MSCs maintaining their properties of stemness and multipotency.
- Published
- 2011
- Full Text
- View/download PDF
40. Kinetic-spectrometric three-dimensional chemiluminescence as an effective analytical tool. Application to the determination of benzo(a)pyrene.
- Author
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Pulgarín JA, Bermejo LF, García MN, and Robles IS
- Abstract
Kinetic and spectroscopic methods were used in combination in this work to develop a new analytical tool for use in chemiluminescence detection processes. Specifically, time-resolved chemiluminescence was used jointly with a stopped-flow assembly in order to monitor the chemiluminescence produced in the oxidation of bis(2,4-dinitrophenyl)oxalate (DNPO) by hydrogen peroxide in the presence of a polycyclic aromatic hydrocarbon. Recording of successive two-dimensional spectra during the emission process and treating the acquired spectral data with dedicated software allows the obtainment of three-dimensional chemiluminescence spectra, a result of the joint use of two analytical techniques. Thus, using a flow cell specifically designed for direct coupling to the charge-coupled device (CCD) detector increases the emission intensity without the need for fibre optics. Also, using dedicated software to process the acquired two-dimensional spectra affords a comprehensive kinetic and spectroscopic characterization of the chemiluminescence signal via the three-dimensional spectrum previously obtained. The analytical potential of this new tool was assessed by application to the chemiluminescent reaction between a peroxyoxalate and an oxidant (hydrogen peroxide); the reaction is induced by benzo(a)pyrene, which was used to determine this polycyclic aromatic hydrocarbon in an organic solvent. A linear calibration graph was obtained between 0.5 and 20 mg L(-1). The limit of detection found to be 3.97 μg L(-1) and a relative standard error of 0.64% and a relative standard deviation of 1.87% were obtained. The results reached testify to the usefulness of the proposed analytical tool for simple determinations and its potential for the resolution of complex mixtures or determinations in complex matrices., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
41. Characterization of StPPI1, a proton pump interactor from Solanum tuberosum L. that is up-regulated during tuber development and by abiotic stress.
- Author
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Muñiz García MN, País SM, Téllez-Iñón MT, and Capiati DA
- Subjects
- Amino Acid Sequence, Blotting, Southern, Cell Membrane enzymology, Gene Expression Profiling, Gene Expression Regulation, Developmental, Gene Expression Regulation, Plant, Genes, Plant genetics, Hydrogen-Ion Concentration, Solanum lycopersicum genetics, Molecular Sequence Data, Organ Specificity genetics, Plant Proteins chemistry, Plant Proteins metabolism, Plant Tubers enzymology, Proton Pumps chemistry, Proton Pumps metabolism, Proton-Translocating ATPases metabolism, Recombinant Proteins metabolism, Sequence Alignment, Solanum tuberosum enzymology, Solanum tuberosum growth & development, Plant Proteins genetics, Plant Tubers genetics, Plant Tubers growth & development, Proton Pumps genetics, Solanum tuberosum genetics, Stress, Physiological genetics, Up-Regulation genetics
- Abstract
Plasma membrane proton pumps (PM H(+)-ATPases) are involved in several physiological processes, such as growth and development, and abiotic stress responses. The major regulators of the PM H(+)-ATPases are proteins of the 14-3-3 family, which stimulate its activity. In addition, a novel interaction partner of the AHA1 PM H(+)-ATPase, named PPI1 (proton pump interactor, isoform 1), was identified in Arabidopsis thaliana. This protein stimulates the activity of the proton pump in vitro. In this work, we report the characterization of an A. thaliana PPI1 homolog in potato (Solanum tuberosum L.) named StPPI1. The full-length coding sequence of StPPI1 was obtained. The open reading frame (ORF) encodes a protein of 629 amino acids showing 50% identity with A. thaliana PPI1 protein. The StPPI1 ORF is divided into seven exons split by six introns. Southern blot analysis suggests that StPPI1 belongs to a family of related genes. Recombinant StPPI1 stimulates H(+)-ATPase activity in vitro. Basal levels of StPPI1 transcripts are observed in all tissues, however, StPPI1 expression is higher in proliferative regions (shoot apex and flower buds), flowers and leaves than in shoots and roots. StPPI1 mRNA levels significantly increase during tuber development. StPPI1 is induced by salt stress and cold. Drought and mechanical wounding slightly increase StPPI1 transcript levels. In addition, the expression of SlPPI1, the tomato homolog of StPPI1, was determined under adverse environmental conditions in tomato plants. SlPPI1 mRNA levels are increased by drought and cold, but are unaffected by salt stress. Mechanical wounding slightly increases SlPPI1 expression.
- Published
- 2011
- Full Text
- View/download PDF
42. Protein phosphatases type 2A mediate tuberization signaling in Solanum tuberosum L. leaves.
- Author
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País SM, García MN, Téllez-Iñón MT, and Capiati DA
- Subjects
- Amino Acid Sequence, Base Sequence, Blotting, Western, Catalytic Domain, DNA Primers, Molecular Sequence Data, Plant Leaves enzymology, Protein Phosphatase 2 chemistry, Reverse Transcriptase Polymerase Chain Reaction, Sequence Homology, Amino Acid, Solanum tuberosum enzymology, Plant Leaves metabolism, Protein Phosphatase 2 metabolism, Signal Transduction, Solanum tuberosum metabolism
- Abstract
Tuber formation in potato (Solanum tuberosum L.) is regulated by hormonal and environmental signals that are thought to be integrated in the leaves. The molecular mechanisms that mediate the responses to tuberization-related signals in leaves remain largely unknown. In this study we analyzed the roles of protein phosphatase type 2A catalytic subunits (PP2Ac) in the leaf responses to conditions that affect tuberization. The responses were monitored by analyzing the expression of the "tuber-specific" genes Patatin and Pin2, which are induced in tubers and leaves during tuber induction. Experiments using PP2A inhibitors, together with PP2Ac expression profiles under conditions that affect tuberization indicate that high sucrose/nitrogen ratio, which promotes tuber formation, increases the transcript levels of Patatin and Pin2, by increasing the activity of PP2As without affecting PP2Ac mRNA or protein levels. Gibberellic acid (GA), a negative regulator of tuberization, down-regulates the transcription of catalytic subunits of PP2As from the subfamily I and decreases their enzyme levels. In addition, GA inhibits the expression of Patatin and Pin2 possibly by a PP2A-independent mechanism. PP2Ac down-regulation by GA may inhibit tuberization signaling downstream of the inductive effects of high sucrose/nitrogen ratio. These results are consistent with the hypothesis that PP2As of the subfamily I may positively modulate the signaling pathways that lead to the transcriptional activation of "tuber-specific" genes in leaves, and act as molecular switches regulated by both positive and negative modulators of tuberization.
- Published
- 2010
- Full Text
- View/download PDF
43. Anti-proliferative effect of extremely low frequency electromagnetic field on preneoplastic lesions formation in the rat liver.
- Author
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Jiménez-García MN, Arellanes-Robledo J, Aparicio-Bautista DI, Rodríguez-Segura MA, Villa-Treviño S, and Godina-Nava JJ
- Subjects
- Animals, Apoptosis radiation effects, Blotting, Western, Caspase 3 metabolism, Cell Cycle radiation effects, Cyclin D1 metabolism, Glutathione S-Transferase pi metabolism, Immunohistochemistry, In Situ Nick-End Labeling, Ki-67 Antigen metabolism, Liver metabolism, Liver pathology, Liver Neoplasms chemically induced, Liver Neoplasms metabolism, Liver Neoplasms pathology, Male, Precancerous Conditions chemically induced, Precancerous Conditions metabolism, Precancerous Conditions pathology, Rats, Rats, Inbred F344, Time Factors, gamma-Glutamyltransferase metabolism, Cell Proliferation radiation effects, Electromagnetic Fields, Liver radiation effects, Liver Neoplasms prevention & control, Precancerous Conditions prevention & control
- Abstract
Background: Recently, extremely low frequency electromagnetic fields (ELF-EMF) have been studied with great interest due to their possible effects on human health. In this study, we evaluated the effect of 4.5 mT-120 Hz ELF-EMF on the development of preneoplastic lesions in experimental hepatocarcinogenesis., Methods: Male Fischer-344 rats were subjected to the modified resistant hepatocyte model and were exposed to 4.5 mT - 120 Hz ELF-EMF. The effects of the ELF-EMF on hepatocarcinogenesis, apoptosis, proliferation and cell cycle progression were evaluated by histochemical, TUNEL assay, caspase 3 levels, immunohistochemical and western blot analyses., Results: The application of the ELF-EMF resulted in a decrease of more than 50% of the number and the area of gamma-glutamyl transpeptidase-positive preneoplastic lesions (P = 0.01 and P = 0.03, respectively) and glutathione S-transferase placental expression (P = 0.01). The number of TUNEL-positive cells and the cleaved caspase 3 levels were unaffected; however, the proliferating cell nuclear antigen, Ki-67, and cyclin D1 expression decreased significantly (P < or = 0.03), as compared to the sham-exposure group., Conclusion: The application of 4.5 mT-120 Hz ELF-EMF inhibits preneoplastic lesions chemically induced in the rat liver through the reduction of cell proliferation, without altering the apoptosis process.
- Published
- 2010
- Full Text
- View/download PDF
44. Changes in VEGF expression and DNA synthesis in hepatocytes from hepatectomized and tumour-bearing mice.
- Author
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García MN, Andrini LB, Inda AM, Ronderos JR, Hijano JC, and Errecalde AL
- Subjects
- Animals, Circadian Rhythm physiology, Hepatectomy, Liver cytology, Liver metabolism, Liver Regeneration, Male, Mice, Mice, Inbred C3H, Mitotic Index, RNA, Messenger metabolism, S Phase, Vascular Endothelial Growth Factor A genetics, DNA biosynthesis, Hepatocytes metabolism, Liver Neoplasms, Experimental metabolism, Vascular Endothelial Growth Factor A metabolism
- Abstract
Transplanted tumours could modify the intensity and temporal distribution of the cellular proliferation in normal cell populations, and partial hepatectomy alters the serum concentrations of substances involved in cellular proliferation, leading to the compensatory liver hyperplasia. The following experiments were designed in order to study the SI (S-phase index) and VEGF (vascular endothelial growth factor) expression in regenerating liver (after partial hepatectomy) of adult male mice bearing a hepatocellular carcinoma, throughout one complete circadian cycle. We used adult male C3H/S-strain mice. After an appropriate period of synchronization, the C3H/S-histocompatible ES2a hepatocellular carcinoma was grafted into the subcutaneous tissue of each animal's flank. To determine the index of SI and VEGF expression of hepatocytes, we used immunohistochemistry. The animals were divided into two experimental groups: Group I, control, hepatectomized animals; Group II, hepatectomized tumour-bearing animals. The statistical analysis of SI and VEGF expression was performed using Anova and Tukey as a postcomparison test. The results show that in the second group, the curve of SI changes the time points for maximum and minimum activity, and the peak of VEGF expression appears before the first group. In conclusion, in the hepatectomized mice, the increases of hepatic proliferation, measured by the SI index, may produce a rise in VEGF expression with the object of generating a vascular network for hepatic regeneration. Lastly, as we have mentioned, in hepatectomized and tumour-bearing mice, the peak of VEGF expression appears before the one of DNA synthesis.
- Published
- 2010
- Full Text
- View/download PDF
45. Simultaneous stopped-flow determination of morphine and naloxone by time-resolved chemiluminescence.
- Author
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Murillo Pulgarín JA, García Bermejo LF, Lemus Gallego JM, and Sánchez García MN
- Subjects
- Calibration, Flow Injection Analysis standards, Formaldehyde, Luminescent Measurements standards, Potassium Permanganate, Sulfuric Acids, Time, Flow Injection Analysis methods, Luminescent Measurements methods, Morphine analysis, Naloxone analysis
- Abstract
The first application of the flow analysis coupled with chemiluminescence detection and based on stopped-flow chemistry to the simultaneous determination of two components, using a two equation system, is described. The proposed method to determine simultaneously morphine and naloxone is based on the chemiluminescence oxidation of these compounds by their reaction with potassium permanganate in an acidic medium. The main feature of the system used is that the recording of the whole chemiluminescence intensity-versus-time profiles can be obtained, using the stopped-flow technique in a continuous-flow system. Then, the chemiluminescent signals obtained at two times of these profiles can be used to determine the concentration of both opiate narcotics. The effect of common emission enhancers on the chemiluminescence emission of these compounds in different acidic media, using the above-mentioned technique, was studied, in order to achieve the best conditions in which, the CL profiles of both compounds should be additive. The parameters selected were sulphuric acid 1.0 mol L(-1), permanganate 0.2 mmolL(-1) and formaldehyde 0.8 mol L(-1). Taken in account the different profiles of the transient CL signal obtained with each compounds, using the selected chemical conditions, two measurement times (1.4 and 4.8s) of these responses curves were considered with the purpose to establish a simple 2 x 2 matrix calculation. Using the chemiluminiscent signals obtained at these times, a linear calibration graph was obtained for each one of the compounds between 0.01 and 1.00 mg L(-1) for morphine and 0.10-1.50 mg L(-1) for naloxone. The present chemiluminescence procedure was applied to the determination of both compounds in mixtures and was found to be satisfactory.
- Published
- 2008
- Full Text
- View/download PDF
46. Multivariate calibration applied to the time-resolved chemiluminescence for the simultaneous determination of morphine and its antagonist naloxone.
- Author
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Murillo Pulgarín JA, García Bermejo LF, and Sánchez García MN
- Subjects
- Acids chemistry, Calibration, Formaldehyde chemistry, Molecular Structure, Morphine chemistry, Potassium chemistry, Temperature, Time Factors, Luminescent Measurements instrumentation, Luminescent Measurements methods, Morphine analysis, Morphine antagonists & inhibitors, Naloxone analysis
- Abstract
A novel alternative for the simultaneous determination of compounds with similar structure is described, using the whole chemiluminescence-time profiles, acquired by the stopped-flow technique, in combination with mathematical treatments of multivariate calibration. The proposed method is based on the chemiluminescent oxidation of morphine and naloxone by their reaction with potassium permanganate in an acidic medium, using formaldehyde as co-factor. The whole chemiluminescence-time profiles, acquired using the stopped-flow technique in a continuous-flow system, allowed the use of the time-resolved chemiluminescence (CL) data in combination with multivariate calibration techniques, as partial least squares (PLS), for the quantitative determination of both opiate narcotics in binary mixtures. In order to achieve overcoat the additivity of the CL profiles and beside to obtain CL profiles for each drug the most separated as possible in the time, the optimum chemical conditions for the CL emission were investigated. The effect of common emission enhancers on the CL emission obtained in the oxidation reaction of these compounds in different acidic media was studied. The parameters selected were sulphuric acid 1.0 mol L(-1), permanganate 0.2 mmol L(-1) and formaldehyde 0.8 mol L(-1). A calibration set of standard samples was designed by combination of a factorial design, with three levels for each factor and a central composite design. Finally, with the aim of validating the chemometric proposed method, a prediction set of binary samples was prepared. Using the multivariate calibration method proposed, the analytes were determined in synthetic samples, obtaining recoveries of 97-109%.
- Published
- 2007
- Full Text
- View/download PDF
47. Evaluation of angiogenesis with the expression of VEGF and CD34 in human non-small cell lung cancer.
- Author
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Inda AM, Andrini LB, García MN, García AL, Fernández Blanco A, Furnus CC, Galletti SM, Prat GD, and Errecalde AL
- Subjects
- Aged, Antigens, CD34 immunology, Biomarkers, Tumor metabolism, Carcinoma, Non-Small-Cell Lung metabolism, Carcinoma, Non-Small-Cell Lung pathology, Female, Humans, Lung Neoplasms metabolism, Lung Neoplasms pathology, Male, Middle Aged, Neovascularization, Pathologic, Antigens, CD34 metabolism, Carcinoma, Non-Small-Cell Lung blood supply, Lung Neoplasms blood supply, Vascular Endothelial Growth Factor A metabolism
- Abstract
Angiogenesis is an essential process in the progression of malignant tumors and the most potent angiogenic factor is the vascular endothelial growth factor (VEGF). On the other hand, the CD34 is an endothelial antigen that has been used to highlight the microvasculature vessel density (MVD) as a direct marker of the degree of neoangiogenesis. In the present study we report the VEGF expression and its relationship with MVD, measured by CD34, in two lineages of non-small cell lung cancer (NSCL): low differentiated adenocarcinomas and epidermoid carcinomas, in order to consider the possibility of using the correlation between both antibodies as a prognostic factor. Tumor sections were stained by immunohistochemistry for CD34 and VEGF. The results showed that the mean value of VEGF for adenocarcinoma was significantly higher than the one for epidermoid carcinoma (p < 0.001). However, the mean of MVD did not show significant differences between both types of tumors. The conventional factors taken into consideration (age over 60, sex, and presence of lymph nodes) was not significantly related to the angiogenic factors examined. In conclusion, we could affirm that CD34 is a better prognostic marker of neoangiogenesis in NSCLC, because both types of tumors have the same clinical prognosis, and so we expected the same behaviour from both markers.
- Published
- 2007
48. DNA synthesis in tongue keratinocytes of hepatectomized and tumor-bearing mice.
- Author
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García MN, Andrini LB, Errecalde AL, and Barbeito CG
- Subjects
- Animals, Bromodeoxyuridine metabolism, Cell Nucleus metabolism, Male, Mice, S Phase, Time Factors, DNA biosynthesis, Hepatectomy methods, Keratinocytes cytology, Neoplasms pathology, Tongue cytology
- Abstract
Tongue keratinocytes have high S-phase and mitotic indices with evident circadian variation. Transplanted tumors modify the intensity and temporal structure of the S-phase index in cell populations in tumor-bearing animals; also, partial hepatectomy changes the concentrations of substances involved in cellular proliferation, leading to compensatory liver hyperplasia. The aim of our study was to analyze the interaction between tumor growth and the liver regeneration that follows partial hepatectomy, and the effects of both these processes on lingual keratinocytes. We used 380 adult male mice divided into six groups: tumor-free and tumor-bearing mice without surgery, with sham hepatectomy, and with partial hepatectomy. Each group was divided into six subgroups, which were killed at 4-h intervals until a circadian cycle was completed (from 26 until 50h post-surgery in the operated animals). Each animal was injected with 5-bromodeoxyuridine (50mg/kg) 1h before it was killed, and tongue samples were obtained and processed for histology. The sections were placed on silanized slides and incubated with the primary antibody Bu 20a (1/100 dilution). The reaction was developed using diaminobenzidine and staining was detected visually. SIs were measured as the number of labeled nuclei per thousand cells. The mean+/-S.E. of each group was calculated. Differences among experimental groups were analyzed by ANOVA and the Student-Newman-Keuls Multiple Comparisons Test. The results show that the presence of a tumor alters the normal circadian curve of SI in lingual keratinocytes, irrespective of whether the mice underwent surgery. This finding has to be considered in drug treatments for neoplasms and in experiments related to growth.
- Published
- 2006
- Full Text
- View/download PDF
49. Comparative study of DNA synthesis and nucleolar organizer regions of sinusoid littoral cells in mouse regenerating liver.
- Author
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Martín CA, Surur JM, García MN, Corrons F, and Badrán AF
- Subjects
- Animals, Bromodeoxyuridine, Cell Proliferation, Hepatectomy, Image Cytometry, Immunohistochemistry, Liver cytology, Liver injuries, Macrophages cytology, Male, Mice, Mice, Inbred C3H, Silver Staining, Time Factors, Cell Nucleolus metabolism, DNA biosynthesis, Liver metabolism, Liver Regeneration physiology, Macrophages metabolism, Nucleolus Organizer Region metabolism
- Abstract
Variations in DNA synthesis (DNAs) and Nucleolar Organizer Regions (NORs) were studied in the littoral cell population from regenerating liver of C3HS inbred mice standardized for periodicity analysis. Immunohistochemical detection of Bromodeoxyuridine (BrdU) with a monoclonal antibody and silver staining of NORs (AgNORs) were assessed by means of a digital image analysis system in histological sections. Tissue samples were obtained every four hours from the 30th to the 54th hours after a partial hepatectomy. The results showed, in both parameters, a gradual increment of the values during the period studied, with highest values (DNAs 107.1 +/- 16.1 SE; AgNORs 77.3 +/- 3.4 SE) located at 16:00/54 Time of Day / Hours Post-Hepatectomy (TD/HPH), which were significantly different (p <0.001) from the values of the first sample (DNAs 38.1 +/- 9.5 SE; AgNORs 27.3 +/- 1.0 SE) taken at 16:00/30 TD/HPH. The results of our experiment demonstrate the existence of a strong correlation of DNA synthesis measured by BrdU immunohistochemistry and AgNORs numbers in sinusoid littoral cells from mouse regenerating liver.
- Published
- 2005
50. Chronobiology of the proliferative events related to angiogenesis in mice liver regeneration after partial hepatectomy.
- Author
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Furnus CC, Inda AM, Andrini LB, García MN, García AL, Badrán AF, and Errecalde AL
- Subjects
- Animals, Cell Division physiology, Hepatectomy methods, Liver cytology, Liver physiology, Liver surgery, Male, Mice, Mice, Inbred C3H, Vascular Endothelial Growth Factor A biosynthesis, Chronobiology Phenomena physiology, Hepatocytes cytology, Hepatocytes physiology, Liver Regeneration physiology, Neovascularization, Physiologic physiology
- Abstract
In liver regeneration the formation of new capillary blood vessels is a fundamental requirement for cellular proliferation. Vascular endothelial growth factor (VEGF) is involved in the events of angiogenesis, the mRNA of which is expressed in both hepatocytes and non-parenchymal cells. In this experimental design we try to establish if during liver regeneration in mouse, the expression of VEGF is produced before or after the hepatocytes proliferation. C3H/S adult male mice were divided in three groups in order to study: VEGF expression; S-phase index (SI); and mitotic activity (MA) of hepatocytes. The results that were analyzed by ANOVA, show that VEGF expression starts to increase 26 h after PH with a peak at 28 h. Furthermore, the DNA synthesis (DNAs) reaches maximal level 42 h after pH, meanwhile the MA of the hepatocytes shows an increase 8h after the DNAs peak. In conclusion, it could be argued that the chronobiology of the events related to liver regeneration in mice started with a release of VEGF by the hepatocytes, followed by its DNAs and mitosis.
- Published
- 2003
- Full Text
- View/download PDF
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