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Papers by Victor Garcia

Acta Otorrinolaringologica (English Edition), 2007

Biochimica et biophysica acta, 2014

The N-acyl conjugates of amino acids and neurotransmitters (NAANs) are a class of endogenous lipi... more The N-acyl conjugates of amino acids and neurotransmitters (NAANs) are a class of endogenous lipid messengers that are expressed in the mammalian central and peripheral nervous system. Hypoxia inducible factor-1α (HIF-1α) is a transcription factor that plays a key role in the cellular adaptation to hypoxia and ischemia, and hypoxic preconditioning through HIF-1α has been shown to be neuroprotective in ischemic models. This study showed that N-acyl-dopamines induce HIF-1α stabilization on human primary astrocytes and neurons as well as in transformed cell lines. N-arachidonoyl-dopamine (NADA)-induced HIF-1α stabilization depends on the dopamine moiety of the molecule and is independent of cannabinoid receptor-1 (CB1) and transient receptor potential vanilloid type I (TRPV1) activation. NADA increases the activity of the E3 ubiquitin ligase seven in absentia homolog-2 (SIAH2), inhibits prolyl-hydroxylase-3 (PHD3) and stabilizes HIF-1α. NADA enhances angiogenesis in endothelial vascular cells and promotes the expression of genes such as erythropoietin (EPO), vascular endothelial growth factor A (VEGFA), heme oxygenase 1 (HMOX-1), hexokinase 2 (HK2) and Bcl-2/E1B-nineteen kiloDalton interacting protein (BNIP3) in primary astrocytes. These findings indicate a link between N-acyl-dopamines and hypoxic preconditioning and suggest that modulation of the N-acyl-dopamine metabolism might prove useful for prevention against hypoxic diseases.

European journal of pharmacology, Jan 5, 2015

N-arachidonoylphenolamine (AM404), a paracetamol lipid metabolite, is a modulator of the endocann... more N-arachidonoylphenolamine (AM404), a paracetamol lipid metabolite, is a modulator of the endocannabinoid system endowed with pleiotropic activities. AM404 is a dual agonist of the Transient Receptor Potential Vanilloid type 1 (TRPV1) and the Cannabinoid Receptor type 1 (CB1) and inhibits anandamide (AEA) transport and degradation. In addition, it has been shown that AM404 also exerts biological activities through TRPV1- and CB1 -independent pathways. In the present study we have investigated the effect of AM404 in the NFAT and NF-κB signaling pathways in SK-N-SH neuroblastoma cells. AM404 inhibited NFAT transcriptional activity through a CB1- and TRPV1-independent mechanism. Moreover, AM404 inhibited both the expression of COX-2 at transcriptional and post-transcriptional levels and the synthesis of PGE2. AM404 also inhibited NF-κB activation induced by PMA/Ionomycin in SK-N-SH cells by targeting IKKβ phosphorylation and activation. We found that Cot/Tlp-2 induced NFAT and COX-2 transcriptional activities were inhibited by AM404. NFAT inhibition paralleled with the ability of AM404 to inhibit MMP-1, -3 and -7 expression, cell migration and invasion in a cell-type specific dependent manner. Taken together, these data reveal that paracetamol, the precursor of AM404, can be explored not only as an antipyretic and painkiller drug but also as a co-adjuvant therapy in inflammatory and cancer diseases.

Acta Otorrinolaringologica (English Edition), 2009

Introduction: Asymptomatic unilateral tonsillar enlargement is usually treated with systematic to... more Introduction: Asymptomatic unilateral tonsillar enlargement is usually treated with systematic tonsillectomy under suspicion of malignancy. Due to the fact that most of the cases are benign pathologies, we set out to study the clinical signs that would help us in the diagnosis in order to avoid unnecessary tonsillectomies. Material and methods: We reviewed 267 tonsillectomies performed from 1996 to 2006 and 30 of these were indicated because of asymmetry. We evaluated risk factors for malignancy: cervical lymphatic node enlargement, sex, age, tonsillar enlargement noticed by the patient, suspicious appearance, systemic symptoms, history of malignancy, and immunocompromise. Results: Histopathologic study revealed 80% to be benign and 20% malignant. The risk factors with the strongest association were enlargement of cervical lymphatic nodes and suspicious appearance of the tonsil. Conclusions: Strict control of a unilateral tonsillar enlargement is possible, but it is mandatory to perform a tonsillectomy when the appearance of the tonsil raises suspicions or there are enlarged lymphatic nodes.

Journal of Biological Chemistry, 2014

Background: STAT3 is constitutively active in castration-resistant prostate cancer and the fungal... more Background: STAT3 is constitutively active in castration-resistant prostate cancer and the fungal metabolite galiellalactone inhibits STAT3 signaling. Results: Galiellalactone binds covalently to one or more cysteines in STAT3 and prevents STAT3 binding to DNA. Conclusion: Galiellalactone inhibits STAT3 signaling by binding directly to STAT3. Significance: Galiellalactone is a promising direct STAT3 inhibitor for treatment of castration-resistant prostate cancer.

… of Biomedicine and …, 2006

A simple, rapid, and reliable TLC method for the separation and determination of sanguinarine has... more A simple, rapid, and reliable TLC method for the separation and determination of sanguinarine has been established. This intensively studied biologically active alkaloid has a wide range of potentially useful medicinal properties, such as antimicrobial, antiinflammatory, and antitumoral activities. Sanguinarine has also been incorporated into expectorant mixtures and has a strong bactericidal effect upon gram-positive bacteria, particularly Bacillus anthracis and staphylococci. These medicinal properties are due to the interaction of sanguinarine with DNA. A fibre-optic-based fluorescence instrument for in situ scanning was used for quantitative measurements. The sanguinarine was determined over the range 5-40 ng and a detection limit of 1.60 ng. The method was applied to the quantification of sanguinarine in tissue culture extracts of Chelidonium majus L.

Acta Otorrinolaringológica Española, 2007

El síndrome del seno silente es una afección muy poco frecuente. Se describe como un enoftalmos u... more El síndrome del seno silente es una afección muy poco frecuente. Se describe como un enoftalmos unilateral secundario a colapso y opacificación del seno maxilar sin síntomas nasosinusales. La obstrucción del complejo osteomeatal es el factor fisiopatológico desencadenante. El diagnóstico se basa en los hallazgos clínicos y radiológicos. El tratamiento irá dirigido a restablecer la ventilación del seno y, si es necesario, corregir el suelo orbitario. Presentamos el caso de una mujer diagnosticada y tratada en nuestro hospital por esta entidad.

Acta Otorrinolaringológica Española, 2009

IntroductionAsymptomatic unilateral tonsillar enlargement is usually treated with systematic tons... more IntroductionAsymptomatic unilateral tonsillar enlargement is usually treated with systematic tonsillectomy under suspicion of malignancy. Due to the fact that most of the cases are benign pathologies, we set out to study the clinical signs that would help us in the diagnosis in order to avoid unnecessary tonsillectomies.

Interactive Distributed Multimedia Systems and Telecommunication Services, 2002

A key issue in any system for distribution of continuous media-on-demand is the capacity of the s... more A key issue in any system for distribution of continuous media-on-demand is the capacity of the system with regard to quality of the service specifications, that is, the number of simultaneous streams the system can provide until degradation of the quality of reproduction and interactivity perceived by the users. This work presents the evaluation of interactive video-on-demand systems, with special attention to limitations caused by the video server. The evaluation is based on a set of metrics designed to determine the number of streams a video server can support under specific requirements of the quality of the service as perceived by the users. To validate the utility of these metrics, a prototype of a news-on-demand service has been built and the load for this kind of systems has been characterised. In addition, a load generator which emulates the concurrent access of several users to the system has been built. The evaluation establishes the relationship between the video server limitations and the quality of the service perceived by the users.

Simulation Modelling Practice and Theory, 2004

This paper describes the steps followed in the development, simulation, and later validation of a... more This paper describes the steps followed in the development, simulation, and later validation of a model for a cable network based on hybrid fiber-coax (HFC) technology, used for data transmission. This work presents a representation of a communication system which has been growing dramatically over recent years and will continue to do so in the near future. The modeling process is based on the analysis of measurements of a cable operator, establishing a direct relationship between model parameters and network characteristics. The modeling technique produces a scalable model capable of simulating the evolution of the real cable network.

Natural iron oxides are very common in nature and are the main components of many minerals, rocks... more Natural iron oxides are very common in nature and are the main components of many minerals, rocks and soils. There are a great variety of these minerals in Peru, especially in the Andes region. The mineral studied was extracted from the Taraco District in the Huancané Province of the Puno Region. The extracted sample is a yellowish mineral with very small particles which is called limonite. X-ray diffraction indicates the presence of goethite as the principal mineralogical phase and quartz as the secondary phase. The 57Fe Mössbauer spectra at room temperature show broadened spectra that were fitted using a distribution model. The most probable field of the magnetic component is 21T, corresponding to the presence of small particles of goethite, confirmed by the 4.2 K spectrum. MS of the calcinated sample in air at 900°C show the presence of two hematite sextets, one related to bulk particles and another to surface particles. Chemical analysis using Scanning Electron Microscopy and Energy Dispersive X-ray Spectrometer indicates that O and Fe are the major components; other elements such as Al, Si, Mg and Ca are also present.

ACM Multimedia Conference, 2002

El diseño de la próxima generación de Barreras Térmicas (BT) depende de la obtención de materiale... more El diseño de la próxima generación de Barreras Térmicas (BT) depende de la obtención de materiales con muy baja conductividad térmica ( ) λ a altas temperaturas (

Lecture Notes in Computer Science, 2003

ABSTRACT This paper describes the traffic model developed to represent the traffic observed on th... more ABSTRACT This paper describes the traffic model developed to represent the traffic observed on the telecommunication network of a cable operator providing data services. The operator network is based on a hybrid fiber coax (HFC) network using ATM technology. The traffic model is based on the measurements taken on the upstream channels of the network and represents the behavior of the subscribers by simulation.

Lecture Notes in Computer Science, 2003

This paper describes the tool developed in order to analyse a video-on-demand streaming service. ... more This paper describes the tool developed in order to analyse a video-on-demand streaming service. The aim of this work is to provide a powerful system to help both the service providers and the communication operators to configure this sort of services. Distributing ...

Fuel, 2007

The objective of the present work was to study the influence of some reaction parameters (tempera... more The objective of the present work was to study the influence of some reaction parameters (temperature, chemical nature of pre-treatment gas, mass catalyst) on the yield of methane reforming with carbon dioxide on Ni (5%)–Ca (1%)/AC at atmospheric pressure. The obtained results show that the best system was pre-treated under He flow at 650 °C and then following the reaction at the same temperature. It was also detected that Ca plays a co-support role inhibiting the deactivation of catalyst at long periods of reaction. It can be concluded that it is possible to employ activated carbon as support for methane dry reformation obtaining representative methane conversions up to 40% at mild experimental conditions.

Acta Otorrinolaringologica (English Edition), 2007

Biochimica et biophysica acta, 2014

The N-acyl conjugates of amino acids and neurotransmitters (NAANs) are a class of endogenous lipi... more The N-acyl conjugates of amino acids and neurotransmitters (NAANs) are a class of endogenous lipid messengers that are expressed in the mammalian central and peripheral nervous system. Hypoxia inducible factor-1α (HIF-1α) is a transcription factor that plays a key role in the cellular adaptation to hypoxia and ischemia, and hypoxic preconditioning through HIF-1α has been shown to be neuroprotective in ischemic models. This study showed that N-acyl-dopamines induce HIF-1α stabilization on human primary astrocytes and neurons as well as in transformed cell lines. N-arachidonoyl-dopamine (NADA)-induced HIF-1α stabilization depends on the dopamine moiety of the molecule and is independent of cannabinoid receptor-1 (CB1) and transient receptor potential vanilloid type I (TRPV1) activation. NADA increases the activity of the E3 ubiquitin ligase seven in absentia homolog-2 (SIAH2), inhibits prolyl-hydroxylase-3 (PHD3) and stabilizes HIF-1α. NADA enhances angiogenesis in endothelial vascular cells and promotes the expression of genes such as erythropoietin (EPO), vascular endothelial growth factor A (VEGFA), heme oxygenase 1 (HMOX-1), hexokinase 2 (HK2) and Bcl-2/E1B-nineteen kiloDalton interacting protein (BNIP3) in primary astrocytes. These findings indicate a link between N-acyl-dopamines and hypoxic preconditioning and suggest that modulation of the N-acyl-dopamine metabolism might prove useful for prevention against hypoxic diseases.

European journal of pharmacology, Jan 5, 2015

N-arachidonoylphenolamine (AM404), a paracetamol lipid metabolite, is a modulator of the endocann... more N-arachidonoylphenolamine (AM404), a paracetamol lipid metabolite, is a modulator of the endocannabinoid system endowed with pleiotropic activities. AM404 is a dual agonist of the Transient Receptor Potential Vanilloid type 1 (TRPV1) and the Cannabinoid Receptor type 1 (CB1) and inhibits anandamide (AEA) transport and degradation. In addition, it has been shown that AM404 also exerts biological activities through TRPV1- and CB1 -independent pathways. In the present study we have investigated the effect of AM404 in the NFAT and NF-κB signaling pathways in SK-N-SH neuroblastoma cells. AM404 inhibited NFAT transcriptional activity through a CB1- and TRPV1-independent mechanism. Moreover, AM404 inhibited both the expression of COX-2 at transcriptional and post-transcriptional levels and the synthesis of PGE2. AM404 also inhibited NF-κB activation induced by PMA/Ionomycin in SK-N-SH cells by targeting IKKβ phosphorylation and activation. We found that Cot/Tlp-2 induced NFAT and COX-2 transcriptional activities were inhibited by AM404. NFAT inhibition paralleled with the ability of AM404 to inhibit MMP-1, -3 and -7 expression, cell migration and invasion in a cell-type specific dependent manner. Taken together, these data reveal that paracetamol, the precursor of AM404, can be explored not only as an antipyretic and painkiller drug but also as a co-adjuvant therapy in inflammatory and cancer diseases.

Acta Otorrinolaringologica (English Edition), 2009

Introduction: Asymptomatic unilateral tonsillar enlargement is usually treated with systematic to... more Introduction: Asymptomatic unilateral tonsillar enlargement is usually treated with systematic tonsillectomy under suspicion of malignancy. Due to the fact that most of the cases are benign pathologies, we set out to study the clinical signs that would help us in the diagnosis in order to avoid unnecessary tonsillectomies. Material and methods: We reviewed 267 tonsillectomies performed from 1996 to 2006 and 30 of these were indicated because of asymmetry. We evaluated risk factors for malignancy: cervical lymphatic node enlargement, sex, age, tonsillar enlargement noticed by the patient, suspicious appearance, systemic symptoms, history of malignancy, and immunocompromise. Results: Histopathologic study revealed 80% to be benign and 20% malignant. The risk factors with the strongest association were enlargement of cervical lymphatic nodes and suspicious appearance of the tonsil. Conclusions: Strict control of a unilateral tonsillar enlargement is possible, but it is mandatory to perform a tonsillectomy when the appearance of the tonsil raises suspicions or there are enlarged lymphatic nodes.

Journal of Biological Chemistry, 2014

Background: STAT3 is constitutively active in castration-resistant prostate cancer and the fungal... more Background: STAT3 is constitutively active in castration-resistant prostate cancer and the fungal metabolite galiellalactone inhibits STAT3 signaling. Results: Galiellalactone binds covalently to one or more cysteines in STAT3 and prevents STAT3 binding to DNA. Conclusion: Galiellalactone inhibits STAT3 signaling by binding directly to STAT3. Significance: Galiellalactone is a promising direct STAT3 inhibitor for treatment of castration-resistant prostate cancer.

… of Biomedicine and …, 2006

A simple, rapid, and reliable TLC method for the separation and determination of sanguinarine has... more A simple, rapid, and reliable TLC method for the separation and determination of sanguinarine has been established. This intensively studied biologically active alkaloid has a wide range of potentially useful medicinal properties, such as antimicrobial, antiinflammatory, and antitumoral activities. Sanguinarine has also been incorporated into expectorant mixtures and has a strong bactericidal effect upon gram-positive bacteria, particularly Bacillus anthracis and staphylococci. These medicinal properties are due to the interaction of sanguinarine with DNA. A fibre-optic-based fluorescence instrument for in situ scanning was used for quantitative measurements. The sanguinarine was determined over the range 5-40 ng and a detection limit of 1.60 ng. The method was applied to the quantification of sanguinarine in tissue culture extracts of Chelidonium majus L.

Acta Otorrinolaringológica Española, 2007

El síndrome del seno silente es una afección muy poco frecuente. Se describe como un enoftalmos u... more El síndrome del seno silente es una afección muy poco frecuente. Se describe como un enoftalmos unilateral secundario a colapso y opacificación del seno maxilar sin síntomas nasosinusales. La obstrucción del complejo osteomeatal es el factor fisiopatológico desencadenante. El diagnóstico se basa en los hallazgos clínicos y radiológicos. El tratamiento irá dirigido a restablecer la ventilación del seno y, si es necesario, corregir el suelo orbitario. Presentamos el caso de una mujer diagnosticada y tratada en nuestro hospital por esta entidad.

Acta Otorrinolaringológica Española, 2009

IntroductionAsymptomatic unilateral tonsillar enlargement is usually treated with systematic tons... more IntroductionAsymptomatic unilateral tonsillar enlargement is usually treated with systematic tonsillectomy under suspicion of malignancy. Due to the fact that most of the cases are benign pathologies, we set out to study the clinical signs that would help us in the diagnosis in order to avoid unnecessary tonsillectomies.

Interactive Distributed Multimedia Systems and Telecommunication Services, 2002

A key issue in any system for distribution of continuous media-on-demand is the capacity of the s... more A key issue in any system for distribution of continuous media-on-demand is the capacity of the system with regard to quality of the service specifications, that is, the number of simultaneous streams the system can provide until degradation of the quality of reproduction and interactivity perceived by the users. This work presents the evaluation of interactive video-on-demand systems, with special attention to limitations caused by the video server. The evaluation is based on a set of metrics designed to determine the number of streams a video server can support under specific requirements of the quality of the service as perceived by the users. To validate the utility of these metrics, a prototype of a news-on-demand service has been built and the load for this kind of systems has been characterised. In addition, a load generator which emulates the concurrent access of several users to the system has been built. The evaluation establishes the relationship between the video server limitations and the quality of the service perceived by the users.

Simulation Modelling Practice and Theory, 2004

This paper describes the steps followed in the development, simulation, and later validation of a... more This paper describes the steps followed in the development, simulation, and later validation of a model for a cable network based on hybrid fiber-coax (HFC) technology, used for data transmission. This work presents a representation of a communication system which has been growing dramatically over recent years and will continue to do so in the near future. The modeling process is based on the analysis of measurements of a cable operator, establishing a direct relationship between model parameters and network characteristics. The modeling technique produces a scalable model capable of simulating the evolution of the real cable network.

Natural iron oxides are very common in nature and are the main components of many minerals, rocks... more Natural iron oxides are very common in nature and are the main components of many minerals, rocks and soils. There are a great variety of these minerals in Peru, especially in the Andes region. The mineral studied was extracted from the Taraco District in the Huancané Province of the Puno Region. The extracted sample is a yellowish mineral with very small particles which is called limonite. X-ray diffraction indicates the presence of goethite as the principal mineralogical phase and quartz as the secondary phase. The 57Fe Mössbauer spectra at room temperature show broadened spectra that were fitted using a distribution model. The most probable field of the magnetic component is 21T, corresponding to the presence of small particles of goethite, confirmed by the 4.2 K spectrum. MS of the calcinated sample in air at 900°C show the presence of two hematite sextets, one related to bulk particles and another to surface particles. Chemical analysis using Scanning Electron Microscopy and Energy Dispersive X-ray Spectrometer indicates that O and Fe are the major components; other elements such as Al, Si, Mg and Ca are also present.

ACM Multimedia Conference, 2002

El diseño de la próxima generación de Barreras Térmicas (BT) depende de la obtención de materiale... more El diseño de la próxima generación de Barreras Térmicas (BT) depende de la obtención de materiales con muy baja conductividad térmica ( ) λ a altas temperaturas (

Lecture Notes in Computer Science, 2003

ABSTRACT This paper describes the traffic model developed to represent the traffic observed on th... more ABSTRACT This paper describes the traffic model developed to represent the traffic observed on the telecommunication network of a cable operator providing data services. The operator network is based on a hybrid fiber coax (HFC) network using ATM technology. The traffic model is based on the measurements taken on the upstream channels of the network and represents the behavior of the subscribers by simulation.

Lecture Notes in Computer Science, 2003

This paper describes the tool developed in order to analyse a video-on-demand streaming service. ... more This paper describes the tool developed in order to analyse a video-on-demand streaming service. The aim of this work is to provide a powerful system to help both the service providers and the communication operators to configure this sort of services. Distributing ...

Fuel, 2007

The objective of the present work was to study the influence of some reaction parameters (tempera... more The objective of the present work was to study the influence of some reaction parameters (temperature, chemical nature of pre-treatment gas, mass catalyst) on the yield of methane reforming with carbon dioxide on Ni (5%)–Ca (1%)/AC at atmospheric pressure. The obtained results show that the best system was pre-treated under He flow at 650 °C and then following the reaction at the same temperature. It was also detected that Ca plays a co-support role inhibiting the deactivation of catalyst at long periods of reaction. It can be concluded that it is possible to employ activated carbon as support for methane dry reformation obtaining representative methane conversions up to 40% at mild experimental conditions.