50 results on '"J. Varona"'
Search Results
2. Riesgo de reactivación de la hepatitis B asociado al tratamiento con corticoides frente a SARS-CoV-2 (COVID-19)
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J Varona Pérez and J M Rodriguez Chinesta
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business.industry ,Medicine ,General Medicine ,business ,Virology - Published
- 2020
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3. Complications Of Treatment Against SARS-CoV-2: Risk Of Hepatitis B Reactivation Associated With Corticosteroids
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J Varona Pérez
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business.industry ,Materials Science (miscellaneous) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,medicine ,Business and International Management ,Hepatitis B ,medicine.disease ,business ,Virology ,Industrial and Manufacturing Engineering - Published
- 2020
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4. Risk of hepatitis B reactivation associated with treatment against SARS-CoV-2 (COVID-19) with corticosteroids⁎
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J Varona Pérez and J M Rodriguez Chinesta
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2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Medicine ,General Medicine ,Hepatitis B ,business ,medicine.disease ,Virology ,Article - Published
- 2020
5. POS-209 OXYSTEROL-BINDING PROTEIN LIKE 7 IN CHRONIC KIDNEY DISEASE
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J. PRESSLY, J. Varona Santos, M. Ge, M. Gurumani, S. Merscher, and A. Fornoni
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Nephrology - Published
- 2022
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6. Peripheral biochemical parameters associated with neuroinflammation and depression in systemic lupus erythematosus subjects
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I. Horrillo, M. Recio-Barbero, J. Cabezas-Garduño, J. Varona, S. Arostegui, R. Pérez, B. Fernández-Davila, I. Querejeta, J.J. Meana, and R. Segarra
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- 2022
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7. Impaired neuropsychological performance in patients with systemic lupus erythematosus with mood disorder: cognitive profile and clinical implications
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M. Recio-Barbero, R. Segarra, J. Cabezas-Garduño, J. Varona, I. Horrillo, J. Meana, and G. Ruiz-Irastorza
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- 2022
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8. SMPDL3b modulates insulin receptor signaling in diabetic kidney disease
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Christopher E. Pedigo, J. Bryn, Gloria Michelle Ducasa, Mengyuan Ge, Christian Faul, Shamroop K. Mallela, Tae Hyun Yoo, C. Garcia Hernandez, Sandra Merscher, Iris D. Zelnik, J. Varona Santos, Alla Mitrofanova, Eden Rosenfeld-Gur, Armando J. Mendez, Jin Ju Kim, Youssef H. Zeidan, Alessia Fornoni, Anthony H. Futerman, Yu Ishimoto, I. Volosenco, Julia Molina, Laura Barisoni, Ingo B. Leibiger, Alexis Sloan, Reiko Inagi, and George W. Burke
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Male ,0301 basic medicine ,Caveolin 1 ,General Physics and Astronomy ,02 engineering and technology ,Diabetic nephropathy ,Sphingomyelin phosphodiesterase ,Mice ,Insulin ,Protein Isoforms ,Diabetic Nephropathies ,lcsh:Science ,Receptor ,Lipid raft ,Mice, Knockout ,Kidney ,Multidisciplinary ,biology ,Chemistry ,Podocytes ,021001 nanoscience & nanotechnology ,3. Good health ,Sphingomyelin Phosphodiesterase ,Treatment Outcome ,medicine.anatomical_structure ,Female ,lipids (amino acids, peptides, and proteins) ,Signal transduction ,0210 nano-technology ,Signal Transduction ,medicine.medical_specialty ,Science ,Ceramides ,General Biochemistry, Genetics and Molecular Biology ,Article ,Cell Line ,03 medical and health sciences ,Antigens, CD ,Internal medicine ,Diabetes mellitus ,medicine ,Animals ,Humans ,Cell Membrane ,Insulin signalling ,General Chemistry ,medicine.disease ,Sphingolipid ,Cyclic Nucleotide Phosphodiesterases, Type 3 ,Receptor, Insulin ,Disease Models, Animal ,Insulin receptor ,030104 developmental biology ,Endocrinology ,biology.protein ,lcsh:Q - Abstract
Sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is a lipid raft enzyme that regulates plasma membrane (PM) fluidity. Here we report that SMPDL3b excess, as observed in podocytes in diabetic kidney disease (DKD), impairs insulin receptor isoform B-dependent pro-survival insulin signaling by interfering with insulin receptor isoforms binding to caveolin-1 in the PM. SMPDL3b excess affects the production of active sphingolipids resulting in decreased ceramide-1-phosphate (C1P) content as observed in human podocytes in vitro and in kidney cortexes of diabetic db/db mice in vivo. Podocyte-specific Smpdl3b deficiency in db/db mice is sufficient to restore kidney cortex C1P content and to protect from DKD. Exogenous administration of C1P restores IR signaling in vitro and prevents established DKD progression in vivo. Taken together, we identify SMPDL3b as a modulator of insulin signaling and demonstrate that supplementation with exogenous C1P may represent a lipid therapeutic strategy to treat diabetic complications such as DKD., Sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is a lipid raft enzyme known to affect membrane lipid composition. Here, Mitrofanova et al. show that increased expression of SMPDL3b in diabetes impairs insulin signaling and ceramide-1-phosphate (C1P) availability in podocytes, and that C1P supplementation protects mice from diabetic kidney disease.
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- 2019
9. Detection of particle clustering in gas–solid systems using shadow-sizing technique
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J. Varona, David Roelant, Seckin Gokaltun, and A. Awwad
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Materials science ,Fluidized bed ,General Chemical Engineering ,Volume fraction ,Particle ,Mechanics ,Fluidized bed combustion ,Porosity ,Simulation ,Magnetosphere particle motion ,Sizing ,Volumetric flow rate - Abstract
A circulating fluidized bed (CFB) was used to study the particle motion in the riser section to simulate flow regimes in a cold gasifier. High speed imaging was used in order to capture the dynamics of the particles in motion. The shadow sizing technique was used that allowed the determination of particle volume fraction and estimating the trajectories at various flow rates in the riser. The formation of clusters in the riser section of the CFB was detected by analyzing the deviation of the particle volume fraction from the mean value. The shadow sizing technique was observed to be an effective method for detecting dynamics of particles in motion and formation of clusters when supported with high-speed imaging capability.
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- 2012
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10. Diseño, fabricación y prueba de una antena de parche para GPS en aplicaciones automotrices Diseño, fabricación y prueba de una antena de parche para GPS en aplicaciones automotrices
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S. V Koshevaya, J. Sánchez-Mondragon, J. Varona, J. Escobedo-Alatorre, J. G. Vera-Dimas, and M. Tecpoyotl-Torres
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lcsh:Social Sciences ,lcsh:H ,polarización circular ,GPS ,Rogers RT/duroid 5880 ,lcsh:Science (General) ,Antena de parche ,lcsh:Q1-390 - Abstract
This work is focused on the development of a prototype patch antenna designed for use asa replacement antenna in automotive Global Positioning Systems (GPS). In simulations andtesting of the prototype, the focus was on the antenna gain. Transmission-reception testingwas done to verify the operation frequency. The prototype was tested with a commercial GPSkit to evaluate its performance as a replacement antenna. Laboratory testing showed that itcomplied with the minimum requirements for both reception and transmission frequencies,while testing on a stationary vehicle showed slight variations when compared to the positiondata obtained using the same kit with its original antenna. In non-stationary testing, positiondeterminations made with the prototype were sufficiently precise for use.Este trabajo se centra en el desarrollo de una antena de parche diseñada para Sistemas de Posicionamiento Global (GPS), con la finalidad de emplearla como antena de reemplazo en aplicaciones automotrices. En las simulaciones y pruebas se pone énfasis en su ganancia. Las pruebas de transmisión-recepción se realizaron para verificar que la frecuencia de operación de la antena fabricada sea la adecuada. Las pruebas con un kit de GPS comercial fueron realizadas para comparar su desempeño como antena de reemplazo. Las pruebas de laboratorio muestran que se cumple con el mínimo requerido para cubrir ambas frecuencias, de recepción y de transmisión, mientras que las pruebas del prototipo, en el techo vehículo sin movimiento, mostraron ligeras variaciones en los datos de posición, comparados con los obtenidos con el kit con su antena original. Las pruebas de viaje mostraron la suficiente precisión en la determinación de la posición para su uso.
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- 2012
11. A NiTiNOL membrane controlled by an external heat source
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Margarita Tecpoyotl-Torres, Miguel Torres-Cisneros, J. G. Vera-Dimas, J. Varona, and Ramon Cabello-Ruiz
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Microelectromechanical systems ,Optics ,Materials science ,business.industry ,Multiphysics ,Thermal ,Joule effect ,Wafer ,Diaphragm (mechanical device) ,Composite material ,Deformation (engineering) ,business ,Thermal expansion - Abstract
The NiTiNOL diaphragm, under two geometries, were simulated on a Silicon wafer and controlled by an external heat source. As the substrate bottom wall heats and conducts heat, the thermal expansion raises the thin layer which can be used as an actuator. The case of heat source applied on the top walls was also considered. The simulations were realized by means of the mechanical and thermal properties of materials. A comparison among the performance of the diaphragm based on the geometries with a plane layer, a layer with a primary boss, and finally with primary and secondary bosses is presented. Each process was simulated in COMSOL Multiphysics. The distribution of deformation using bosses is similar to the analyzed cases using pressure instead of heat. The maximum obtained displacement for NiTiNOL is of approximately 2.5 micrometers at 343°K, at the same conditions, Silicon case reaches 0.9 μm. The diaphragm behavior is also compared with the cases of Silicon and Cu-Al-Ni. Our interest in the development of MEM actuators only controlled by external heat sources is due to several reasons. At first, because these clean energy sources sometimes reaches high density values, but they have not been well-spent. The most of MEMS thermal actuators need a current flow to heat the MEM device, by means of the Joule effect, and produce the corresponding thermal expansion. In this paper, the displacement depends on the external source, in accordance with the mechanical and electrical properties of the used materials.
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- 2012
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12. Automated semi-spherical irradiance meter
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J. G. Vera-Dimas, Ramon Cabello-Ruiz, Jesus Escobedo-Alatorre, J. Varona, and Margarita Tecpoyotl-Torres
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LED lamp ,Optics ,Computer science ,business.industry ,law ,Acoustics ,Detector ,Irradiance ,business ,law.invention - Abstract
In this semi-spherical meter, a single detector is used to realize all measurements, which is located on the extreme of a rectangular ring (assumed as joined two mobile branches in order to compensate the weights), describing half-meridians from 0° up to 170°. The illumination source under test is located at the center of the mobile support, which can rotate 360° horizontally. The two combined movements allow us to obtain a semi-spherical geometry. The number of measurement points is determined by the two step-motors located under the mobile support of the luminary and on one of the two fixed arms, which support the mobile rectangular ring, respectively. The mechanical arrangement has the enough rigidity to support the precision required for the acquisition stage, based on a dsPIC. The main advantages of this arrange are: Its low costs (using recyclable materials only such as "electronic waste"), a reliable detection based on a single photo-detector, with an integrated amplification stage, and the mechanical design. The received power by the detector is useful to obtain the irradiance profile of the lighting sources under test. The semi-spherical geometry of the meter makes it useful for the analysis of directive and non directive sources, in accordance with the angle described by the mobile ring. In this work, special attention is given to LED lamps due to its impact in several sceneries of the daily life. A comparison between the irradiance patterns of two LED lamps is also given.
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- 2011
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13. Antenna of adjustable bandwidth based on a pentagonal array
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J. Varona, J. J. Sánchez-Mondragón, O. García-García, Rafael Vargas-Bernal, J. G. Vera-Dimas, Margarita Tecpoyotl-Torres, R. Cabello Ruiz, Miguel Torres-Cisneros, and Jesus Escobedo-Alatorre
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Patch antenna ,Antenna array ,Microstrip antenna ,Computer science ,Acoustics ,Bandwidth (signal processing) ,Impedance matching ,Antenna noise temperature ,Center frequency ,Antenna tuner - Abstract
Antenna characteristics are chosen according to the features determined by the systems where they will be used. While some systems require a very narrow bandwidth, others may operate with a much wider bandwidth. Some techniques used for increasing the bandwidth of a given antenna have considered mechanical adjustment of the air layer thickness, with the consequent change on the effective permittivity and performance. Some other systems consider a suitable choice of feeding techniques and impedance matching network. However, approaches for reducing the bandwidth have not received the same level of attention. Narrow bandwidth antennas are of particular interest in security and surveillance systems. In this work we present a technique, based on the design of a pentagonal antenna array, which allows for adjusting the bandwidth in either direction. The array is formed by an inner patch designed at the desired operating frequency of the system and a gap coupled external ring centered at a different frequency (lower or very near the operating frequency), which determines the potential bandwidth increment or decrement. The feed point is located on the inner patch. As a proof-of-concept, this work offers a tuning range that goes from -40% of the center frequency up to +50% of the center operating frequency of the patch antenna. The single patch antenna of this work was designed and simulated at an operating frequency of 4.9 GHz on RT/Duroid 5880.
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- 2011
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14. Generation of irradiance patterns using a semi-spherical meter of two degrees of freedom
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J. J. Sánchez-Mondragón, J. Varona, Miguel Torres-Cisneros, J. G. Vera-Dimas, Ramon Cabello-Ruiz, Margarita Tecpoyotl-Torres, and Jesus Escobedo-Alatorre
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business.industry ,Computer science ,Computer programming ,Detector ,Irradiance ,Photodetector ,law.invention ,Data acquisition ,Optics ,Rigidity (electromagnetism) ,law ,Stepper ,business ,Light-emitting diode - Abstract
The meter device presented in this work consists of a photo-detector mounted on the mechanism of a mobile rectangular arc. One stepper motor located on the lateral axis of the device displaces the sensor along a semi-circular trajectory of 170°, almost half meridians. Another motor located at the base of the device enables 360° rotation of the illumination source under test. This arrangement effectively produces a semi-spherical volume for the sensor to move within. The number of measurement points is determined by programming the two stepper motors. Also, the use of a single photo-sensor ensures uniformity in the measurements. The mechanical structure provides enough rigidity for supporting the accuracy required by the data acquisition circuitry based on a DSPIC. Measurement of illumination sources of different sizes is possible by using adjustable lengths of the mobile base and the ring for a maximum lamp length of 0.16 m. Because this work is partially supported by a private entity interested in the characterization of its products, especial attention has been given to the luminaries based on LED technology with divergent beams. The received power by the detector is useful to obtain the irradiance profile of the lighting source under test. The meter device presented herein is a low-cost prototype designed and fabricated using recyclable materials only such as "electronic waste".
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- 2011
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15. A MEM actuator based on a membrane, controlled by an external heath source
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E. Murphy-Perez, Margarita Tecpoyotl-Torres, J. Varona-Salazar, and Anas A. Hamoui
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Membrane ,Materials science ,Deflection (engineering) ,Multiphysics ,Heat transfer ,Thermal ,Composite material ,Actuator ,Material properties ,Thermal expansion - Abstract
The MEM actuator is controlled by an external heat source, such as the heat gradients present in some electronic systems. As the substrate bottom is heated, the thermal expansion rises the membrane, which can be used as an actuator. The analysis was realized by means of mechanical and thermal properties of materials. We also present the effect of the physical dimensions of the walls and, thickness and the length of the membrane. The process was simulated in COMSOL multiphysics. The membrane central deflection results, using different membrane materials, had been shown the use of Cr membrane as the best choice.
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- 2008
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16. Preliminary Experimental Analysis of Soil Stabilizers for Contamination Control
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Leonel Lagos, A. Zidan, J. Varona, R. Gudavalli, and Kuang-His Wu
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Remedial action ,Engineering ,Waste management ,Soil test ,business.industry ,Hanford Site ,Environmental remediation ,Soil water ,Environmental engineering ,Environmental restoration ,business ,Soil contamination ,Groundwater - Abstract
A major focus of Department of Energy's (DOE's) environmental management mission at the Hanford site involves characterizing and remediating contaminated soil and groundwater; stabilizing contaminated soil; remediating disposal sites; decontaminating and decommissioning structures, and demolishing former plutonium production process buildings, nuclear reactors, and separation plants; maintaining inactive waste sites; transitioning facilities into the surveillance and maintenance program; and mitigating effects to biological and cultural resources from site development and environmental cleanup and restoration activities. For example, a total of 470,914 metric tons of contaminated soil from 100 Areas remediation activities were disposed at the Environmental Restoration Disposal Facility (ERDF) during 2004. The Applied Research Center (ARC) at Florida International University (FIU) is supporting the Hanford's site remediation program by analyzing the effectiveness of several soil stabilizers (fixatives) for contamination control during excavation activities. The study is focusing on determining the effects of varying soil conditions, temperature, humidity and wind velocity on the effectiveness of the candidate stabilizers. The test matrix consists of a soil penetration-depth study, wind tunnel experiments for determination of threshold velocity, and temperature and moisture-controlled drying/curing experiments. These three set of experiments are designed to verify performance metrics, as well as provide insight into what fundamental forcesmore » are altered by the use of the stabilizer. This paper only presents the preliminary results obtained during wind tunnel experiments using dry Hanford soil samples (with 2.7% moisture by weight). These dry soil samples were exposed to varying wind speeds from 2.22 m/sec to 8.88 m/sec. Furthermore, airborne particulate data was collected for the dry Hanford soil experiments using an aerosol analyzer instrument. (authors)« less
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- 2006
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17. Radiologic manifestations of hyperparathyroidism
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E, Vázquez Quintana, H, Pagán Sáez, M T, Meléndez, F, Bayrón Vélez, and M J, Varona
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Adenoma ,Adult ,Male ,Hyperparathyroidism ,Carcinoma ,Magnetic Resonance Imaging ,Mediastinal Neoplasms ,Diagnosis, Differential ,Parathyroid Glands ,Parathyroid Neoplasms ,Humans ,Female ,Radiography, Thoracic ,Tomography, X-Ray Computed - Published
- 1995
18. Francisco Bilbao: Revolucionario de América. By Alberto J. Varona. (Panamá, República de Panamá: Ediciones Excelsior, 1973. Pp. 457. Paper edition. No price.)
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Harold Eugene Davis and Alberto J. Varona
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Cultural Studies ,History - Published
- 1976
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19. Francisco Bilbao, revolucionario de America: Vida y pensamiento, estudio de sus ensayos y trabajos periodisticos
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Vincent Peloso and Alberto J. Varona
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Archeology ,History ,Museology - Published
- 1977
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20. Francisco Bilbao, revolucionario de America
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Alberto J. Varona and Gaston Fernandez-Torriente
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Linguistics and Language ,Education - Published
- 1975
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21. An uncommon cause of persistent infection by Trichomonas vaginalis .
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Varona J, Barberá MJ, and López de Munain J
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- Humans, Female, Adult, Trichomonas Infections diagnosis, Trichomonas Infections drug therapy, Trichomonas Infections parasitology, Metronidazole therapeutic use, Antiprotozoal Agents therapeutic use, Treatment Outcome, Trichomonas vaginalis isolation & purification, Trichomonas Vaginitis drug therapy, Trichomonas Vaginitis diagnosis
- Abstract
Trichomonas vaginalis infection typically exhibits a favorable response to treatment. Nonetheless, there are instances where complete eradication proves challenging, necessitating multiple treatment cycles. Understanding patient history and conducting thorough examinations are crucial in identifying the reasons behind therapeutic failures. We present a case study involving a patient with persistent trichomoniasis despite multiple treatment cycles, attributed to the presence of an intrauterine device inserted several years prior. This case underscores the intricacies involved in managing recurrent Trichomonas vaginalis infections and the importance of a comprehensive evaluation., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2025
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22. PACOPED QL: Development and evaluation of the quality-of-life scale for children with life-threatening illnesses.
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Riera-Negre L, Varona J, Rosselló MR, and Verger S
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- Humans, Child, Female, Surveys and Questionnaires, Male, Reproducibility of Results, Cross-Sectional Studies, Adolescent, Pilot Projects, Child, Preschool, Pediatrics methods, Pediatrics standards, Chronic Disease psychology, Quality of Life psychology, Psychometrics instrumentation, Psychometrics methods, Psychometrics standards, Palliative Care methods, Palliative Care psychology, Palliative Care standards
- Abstract
Objectives: This study aims to validate the Palliative and Complex Chronic Pediatric Patients QoL Inventory (PACOPED QL), a new quality-of-life (QoL) assessment tool for pediatric palliative patients with complex chronic conditions. The goal is to create a comprehensive and inclusive instrument tailored to this unique population, addressing the gap in existing tools that do not meet these specific needs., Methods: The validation process included a literature review and consultations with experts. A pilot study refined the items, followed by a cross-sectional study involving pediatric palliative patients and their caregivers. Statistical analyses, such as Cronbach's alpha for internal consistency and exploratory factor analysis for structural validity, were utilized., Results: The PACOPED QL, comprising 50 items across 8 domains and 6 subdomains, demonstrated strong reliability with Cronbach's alpha and Guttman split-half reliability both exceeding .9. Validity assessments confirmed its suitability for children with complex illnesses. The tool was refined through expert consultations and pilot testing, reducing items from an initial 85 to a final 50, ensuring relevance and clarity., Significance of Results: The PACOPED QL shows strong reliability and validity in assessing QoL in pediatric palliative patients. Its comprehensive structure makes it a promising tool for clinical practice and research, addressing a critical need for a tailored assessment in this population. The instrument's robust psychometric properties indicate its potential utility in improving the QoL assessment and care for children with life-threatening illnesses. Further studies are encouraged to confirm its effectiveness across various settings.
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- 2025
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23. Clinical Predictors of Mood Disorders and Prevalence of Neuropsychiatric Symptoms in Patients with Systemic Lupus Erythematosus.
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Recio-Barbero M, Cabezas-Garduño J, Varona J, Ruiz-Irastorza G, Horrillo I, Meana JJ, Santos-Zorrozúa B, and Segarra R
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Background/Objectives: We aimed to determine the prevalence and clinical correlations of mood disorders in a sample of systemic lupus erythematosus (SLE) patients. Hence, we hypothesized that the prevalence of mood disorders would be lower than reported in the literature and that patients would remain clinically stable and show less damage accrual despite low-dose corticosteroid prescription. Methods: In total, 92 SLE outpatients gave informed consent to participate in this cross-sectional study. Psychiatric and autoimmune clinical data were obtained, and a structured psychiatric interview was performed. The main clinical scales for the assessment of clinical symptomatology were included. To examine the potential relationships of presenting a mood disorder in SLE, clinical correlations and multivariate analyses were performed. Results: Mood disorders were the most prevalent disorder reported by SLE patients (16%), followed by adjustment disorders (5%). A significant proportion of patients presented psychosocial disturbances that did not meet the ICD-10 criteria for psychiatric diagnosis. According to the cut-off criterion for the Montgomery-Åsberg Depression Rating Scale (MADRS), up to 27% of the sample met the clinical criteria for depression. The multivariate analysis revealed a relationship between the presence of a mood disorder with total scores of the MADRS and the Young Mania Rating Scale (YMRS). Conclusions: The prevalence of mood disorders in patients with SLE was lower than previously reported. Although self-report clinical scales are useful for assessing clinical symptomatology, they should not be used in place of a comprehensive standardized interview conducted by a trained mental health specialist. Multidisciplinary teamwork is required for the early identification and therapeutic management of autoimmune patients with neuropsychiatric disorders.
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- 2024
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24. Single-Cell Analyses Offer Insights into the Different Remodeling Programs of Arteries and Veins.
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Rojas MG, Pereira-Simon S, Zigmond ZM, Varona Santos J, Perla M, Santos Falcon N, Stoyell-Conti FF, Salama A, Yang X, Long X, Duque JC, Salman LH, Tabbara M, Martinez L, and Vazquez-Padron RI
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- Humans, Fibroblasts metabolism, Male, Female, Middle Aged, Single-Cell Analysis, Arteries metabolism, Veins metabolism, Myocytes, Smooth Muscle metabolism, Vascular Remodeling
- Abstract
Arteries and veins develop different types of occlusive diseases and respond differently to injury. The biological reasons for this discrepancy are not well understood, which is a limiting factor for the development of vein-targeted therapies. This study contrasts human peripheral arteries and veins at the single-cell level, with a focus on cell populations with remodeling potential. Upper arm arteries (brachial) and veins (basilic/cephalic) from 30 organ donors were compared using a combination of bulk and single-cell RNA sequencing, proteomics, flow cytometry, and histology. The cellular atlases of six arteries and veins demonstrated a 7.8× higher proportion of contractile smooth muscle cells (SMCs) in arteries and a trend toward more modulated SMCs. In contrast, veins showed a higher abundance of endothelial cells, pericytes, and macrophages, as well as an increasing trend in fibroblasts. Activated fibroblasts had similar proportions in both types of vessels but with significant differences in gene expression. Modulated SMCs and activated fibroblasts were characterized by the upregulation of MYH10 , FN1 , COL8A1 , and ITGA10 . Activated fibroblasts also expressed F2R , POSTN , and COMP and were confirmed by F2R/CD90 flow cytometry. Activated fibroblasts from veins were the top producers of collagens among all fibroblast populations from both types of vessels. Venous fibroblasts were also highly angiogenic, proinflammatory, and hyper-responders to reactive oxygen species. Differences in wall structure further explain the significant contribution of fibroblast populations to remodeling in veins. Fibroblasts are almost exclusively located outside the external elastic lamina in arteries, while widely distributed throughout the venous wall. In line with the above, ECM-targeted proteomics confirmed a higher abundance of fibrillar collagens in veins vs. more basement ECM components in arteries. The distinct cellular compositions and transcriptional programs of reparative populations in arteries and veins may explain differences in acute and chronic wall remodeling between vessels. This information may be relevant for the development of antistenotic therapies.
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- 2024
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25. Empagliflozin reduces podocyte lipotoxicity in experimental Alport syndrome.
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Ge M, Molina J, Kim JJ, Mallela SK, Ahmad A, Varona Santos J, Al-Ali H, Mitrofanova A, Sharma K, Fontanesi F, Merscher S, and Fornoni A
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- Humans, Mice, Animals, Glucose toxicity, Glucose metabolism, Podocytes metabolism, Nephritis, Hereditary drug therapy, Nephritis, Hereditary metabolism, Diabetes Mellitus, Type 2 metabolism, Sodium-Glucose Transporter 2 Inhibitors pharmacology, Sodium-Glucose Transporter 2 Inhibitors metabolism
- Abstract
Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are anti-hyperglycemic agents that prevent glucose reabsorption in proximal tubular cells. SGLT2i improves renal outcomes in both diabetic and non-diabetic patients, indicating it may have beneficial effects beyond glycemic control. Here, we demonstrate that SGLT2i affects energy metabolism and podocyte lipotoxicity in experimental Alport syndrome (AS). In vitro, we found that the SGLT2 protein was expressed in human and mouse podocytes to a similar extent in tubular cells. Newly established immortalized podocytes from Col4a3 knockout mice (AS podocytes) accumulate lipid droplets along with increased apoptosis when compared to wild-type podocytes. Treatment with SGLT2i empagliflozin reduces lipid droplet accumulation and apoptosis in AS podocytes. Empagliflozin inhibits the utilization of glucose/pyruvate as a metabolic substrate in AS podocytes but not in AS tubular cells. In vivo, we demonstrate that empagliflozin reduces albuminuria and prolongs the survival of AS mice. Empagliflozin-treated AS mice show decreased serum blood urea nitrogen and creatinine levels in association with reduced triglyceride and cholesterol ester content in kidney cortices when compared to AS mice. Lipid accumulation in kidney cortices correlates with a decline in renal function. In summary, empagliflozin reduces podocyte lipotoxicity and improves kidney function in experimental AS in association with the energy substrates switch from glucose to fatty acids in podocytes., Competing Interests: MG, JM, JK, SM, AA, JV, HA, AM, FF No competing interests declared, KS founder of SygnaMap, SM is an inventor on pending (PCT/US2019/032215; US 17/057,247; PCT/US2019/041730; PCT/US2013/036484; US 17/259,883; US17/259,883; JP501309/2021, EU19834217.2; CN-201980060078.3; CA2,930,119; CA3,012,773,CA2,852,904) or issued patents (US10,183,038 and US10,052,345) aimed at preventing and treating renal disease. They stand to gain royalties from their future commercialization. SM holds indirect equity interest in, and potential royalty from, ZyVersa Therapeutics, Inc by virtue of assignment and licensure of a patent estate. SM is supported by Aurinia Pharmaceuticals Inc, AF is an inventor on pending (PCT/US2019/032215; US 17/057,247; PCT/US2019/041730; PCT/US2013/036484; US 17/259,883; US17/259,883; JP501309/2021, EU19834217.2; CN-201980060078.3; CA2,930,119; CA3,012,773,CA2,852,904) or issued patents (US10,183,038 and US10,052,345) aimed at preventing and treating renal disease. They stand to gain royalties from their future commercialization. AF is Vice-President of L&F Health LLC and is a consultant for ZyVersa Therapeutics, Inc. ZyVersa Therapeutics, Inc has licensed worldwide rights to develop and commercialize hydroxypropyl-beta-cyclodextrin from L&F Research for the treatment of kidney disease. AF also holds equities in Renal 3 River Corporation. AF and SM are supported by Aurinia Pharmaceuticals Inc, (© 2023, Ge et al.)
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- 2023
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26. The Influence of Mobile Device Type on Camera-Based Monitoring of Neck Movements for Cervical Rehabilitation.
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Roig-Maimó MF, Salinas-Bueno I, Mas-Sansó R, Varona J, and Martínez-Bueso P
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- Computers, Handheld, Mobile Applications, Telemedicine
- Abstract
We developed a mobile application for cervical rehabilitation that uses a non-invasive camera-based head-tracker sensor for monitoring neck movements. The intended user population should be able to use the mobile application in their own mobile device, but mobile devices have different camera sensors and screen dimensions that could affect the user performance and neck movement monitoring. In this work, we studied the influence of mobile devices type on camera-based monitoring of neck movements for rehabilitation purposes. We conducted an experiment to test whether the characteristics of a mobile device affect neck movements when using the mobile application with the head-tracker. The experiment consisted of the use of our application, containing an exergame, in three mobile devices. We used wireless inertial sensors to measure the real-time neck movements performed while using the different devices. The results showed that the effect of device type on neck movements was not statistically significant. We included the sex factor in the analysis, but there was no statistically significant interaction between sex and device variables. Our mobile application proved to be device-agnostic. This will allow intended users to use the mHealth application regardless of the type of device. Thus, future work can continue with the clinical evaluation of the developed application to analyse the hypothesis that the use of the exergame will improve therapeutic adherence in cervical rehabilitation.
- Published
- 2023
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27. A Robust Phenotypic Screening Assay Utilizing Human Podocytes to Identify Agents that Modulate Lipid Droplets.
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Gurumani M, Mallela SK, Varona J, Merscher S, Fornoni A, and Al-Ali H
- Subjects
- Humans, Lipid Droplets metabolism, Cell Differentiation, Lipid Metabolism, Podocytes metabolism, Kidney Diseases metabolism
- Abstract
Lipid droplets (LDs), initially thought to be mere lipid storage structures, are highly dynamic organelles with complex functions that control cell fate and behavior. In recent years, their relevance as therapeutic targets for a wide array of human diseases has been well established. Consequently, efforts to develop tools to study them have intensified, including assays that can accurately track LD levels in clinically relevant cell-based models. We previously reported that LD accumulation destines podocytes for lipotoxicity and cell death in renal diseases of metabolic and nonmetabolic origin. We also showed that LD accumulation in those cells serves as both a marker for disease progression and as a therapeutic target. Here, we describe a robust phenotypic screening method, using differentiated human podocytes, for identifying small-molecule compounds that rescue podocytes from LD accumulation and lipotoxicity under cellular stress. Major assay advances include 1) the use of a solvatochromic dye to improve LD staining, reduce background noise, and improve detection accuracy, 2) use of confocal imaging to reduce vertical overlap of LDs and enable accurate counting, 3) combining membrane and cytoskeleton stains to improve cell segmentation in confocal mode, and 4) use of an optimized spot detection algorithm that requires minimal configuration per individual run. The assay is robust and yields a Z-factor that is consistently >0.5., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2023
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28. In the shadow of the pandemic.
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Dueña L, Varona J, Bereciartua E, and López L
- Subjects
- Pandemics
- Published
- 2022
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29. Eurolupus cyclophosphamide plus repeated pulses of methyl-prednisolone for the induction therapy of class III, IV and V lupus nephritis.
- Author
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Ruiz-Irastorza G, Dueña-Bartolome L, Dunder S, Varona J, Gomez-Carballo C, Dominguez-Cainzos J, Rodrigo-Manjon A, Bueno L, Richez C, Duffau P, Blanco P, and Lazaro E
- Subjects
- Cyclophosphamide adverse effects, Humans, Immunosuppressive Agents adverse effects, Induction Chemotherapy, Methylprednisolone adverse effects, Mycophenolic Acid therapeutic use, Observational Studies as Topic, Remission Induction, Treatment Outcome, Lupus Nephritis drug therapy
- Abstract
Objective: To study whether adding repeated 125 mg methyl-prednisolone pulses (MP) to Eurolupus fortnightly intravenous cyclophosphamide (CYC) improves remission of lupus nephritis (LN) compared with recommended schedules., Methods: Observational comparative study of patients with biopsy-confirmed class III, IV or V LN: 30 in the mycophenolate (MMF) group, 25 in the CYC group and 38 in the CYC-MP group. The main efficacy outcome was complete response at 12 months., Results: Patients in the CYC-MP group received lower doses of prednisone within 6 months (mean 8.5 mg/d, vs. 15 mg/d in the MMF group vs. 24 mg/d in the CYC group, respectively). The complete response rates at 12 months were: CYC-MP 86%; CYC 56%; MMF 47% (p = 0.002) at Pr/Cr <0.5; CYC-MP 86%; CYC 65%; MMF 63% (p = 0.07) at Pr/Cr ≤0.7. The cumulative 12-month response rates for the CYC-MP, CYC and MMF groups were, respectively, 0.90, 0.58 and 0.63 (p = 0.004). In the adjusted Cox model, patients receiving CYC-MP were more likely to achieve complete response at Pr/Cr <0.5 than those in the MMF (HR vs. CYC-MP 0.33, 95%CI 0.16-0.65) and the CYC groups (HR vs. CYC-MP 0.47, 95%CI 0.21-1.04). Glucocorticoid-related toxicity was seen in 2.6% of the CYC-MP group, 24% of the CYC group and 20% of the MMF group (p = 0.029)., Conclusion: The addition MP of 125 mg to each fortnightly dose of 500 mg of CYC improves response rates and reduces the need for oral glucocorticoids in patients with class III, IV and V LN., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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30. Compounds targeting OSBPL7 increase ABCA1-dependent cholesterol efflux preserving kidney function in two models of kidney disease.
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Wright MB, Varona Santos J, Kemmer C, Maugeais C, Carralot JP, Roever S, Molina J, Ducasa GM, Mitrofanova A, Sloan A, Ahmad A, Pedigo C, Ge M, Pressly J, Barisoni L, Mendez A, Sgrignani J, Cavalli A, Merscher S, Prunotto M, and Fornoni A
- Subjects
- ATP Binding Cassette Transporter 1 genetics, Animals, Biological Transport drug effects, Cells, Cultured, Disease Models, Animal, HEK293 Cells, Humans, Kidney drug effects, Kidney metabolism, Kidney pathology, Mice, 129 Strain, Mice, Knockout, Molecular Structure, Niacinamide chemistry, Niacinamide pharmacology, Organic Chemicals chemical synthesis, Organic Chemicals chemistry, Podocytes cytology, RNA Interference, Receptors, Steroid genetics, Receptors, Steroid metabolism, THP-1 Cells, Mice, Oxysterol Binding Proteins, ATP Binding Cassette Transporter 1 metabolism, Cholesterol metabolism, Diabetic Nephropathies metabolism, Organic Chemicals pharmacology, Podocytes metabolism, Proteinuria metabolism, Receptors, Steroid antagonists & inhibitors
- Abstract
Impaired cellular cholesterol efflux is a key factor in the progression of renal, cardiovascular, and autoimmune diseases. Here we describe a class of 5-arylnicotinamide compounds, identified through phenotypic drug discovery, that upregulate ABCA1-dependent cholesterol efflux by targeting Oxysterol Binding Protein Like 7 (OSBPL7). OSBPL7 was identified as the molecular target of these compounds through a chemical biology approach, employing a photoactivatable 5-arylnicotinamide derivative in a cellular cross-linking/immunoprecipitation assay. Further evaluation of two compounds (Cpd A and Cpd G) showed that they induced ABCA1 and cholesterol efflux from podocytes in vitro and normalized proteinuria and prevented renal function decline in mouse models of proteinuric kidney disease: Adriamycin-induced nephropathy and Alport Syndrome. In conclusion, we show that small molecule drugs targeting OSBPL7 reveal an alternative mechanism to upregulate ABCA1, and may represent a promising new therapeutic strategy for the treatment of renal diseases and other disorders of cellular cholesterol homeostasis., (© 2021. The Author(s).)
- Published
- 2021
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31. Laughter and smiling facial expression modelling for the generation of virtual affective behavior.
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Mascaró M, Serón FJ, Perales FJ, Varona J, and Mas R
- Subjects
- Computer Graphics, Computer Simulation, Emotions physiology, Face physiology, Humans, Pictorial Works as Topic, Software, Databases, Factual, Facial Expression, Laughter physiology, Smiling physiology
- Abstract
Laughter and smiling are significant facial expressions used in human to human communication. We present a computational model for the generation of facial expressions associated with laughter and smiling in order to facilitate the synthesis of such facial expressions in virtual characters. In addition, a new method to reproduce these types of laughter is proposed and validated using databases of generic and specific facial smile expressions. In particular, a proprietary database of laugh and smile expressions is also presented. This database lists the different types of classified and generated laughs presented in this work. The generated expressions are validated through a user study with 71 subjects, which concluded that the virtual character expressions built using the presented model are perceptually acceptable in quality and facial expression fidelity. Finally, for generalization purposes, an additional analysis shows that the results are independent of the type of virtual character's appearance., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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32. APOL1 risk variants affect podocyte lipid homeostasis and energy production in focal segmental glomerulosclerosis.
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Ge M, Molina J, Ducasa GM, Mallela SK, Varona Santos J, Mitrofanova A, Kim JJ, Liu X, Sloan A, Mendez AJ, Banerjee S, Liu S, Szeto HH, Shin MK, Hoek M, Kopp JB, Fontanesi F, Merscher S, and Fornoni A
- Subjects
- Black or African American genetics, Animals, Glomerulosclerosis, Focal Segmental genetics, Glomerulosclerosis, Focal Segmental physiopathology, Homeostasis, Humans, Mice, Mice, Transgenic, Mitochondria physiology, Podocytes physiology, Proteinuria, Triglycerides metabolism, Apolipoprotein L1 genetics, Genetic Variation, Glomerulosclerosis, Focal Segmental metabolism, Lipid Metabolism, Mitochondria metabolism, Podocytes metabolism
- Abstract
Lipotoxicity was recently reported in several forms of kidney disease, including focal segmental glomerulosclerosis (FSGS). Susceptibility to FSGS in African Americans is associated with the presence of genetic variants of the Apolipoprotein L1 gene (APOL1) named G1 and G2. If and how endogenous APOL1 may alter mitochondrial function by the modifying cellular lipid metabolism is unknown. Using transgenic mice expressing the APOL1 variants (G0, G1 or G2) under endogenous promoter, we show that APOL1 risk variant expression in transgenic mice does not impair kidney function at baseline. However, APOL1 G1 expression worsens proteinuria and kidney function in mice characterized by the podocyte inducible expression of nuclear factor of activated T-cells (NFAT), which we have found to cause FSGS. APOL1 G1 expression in this FSGS-model also results in increased triglyceride and cholesterol ester contents in kidney cortices, where lipid accumulation correlated with loss of renal function. In vitro, we show that the expression of endogenous APOL1 G1/G2 in human urinary podocytes is associated with increased cellular triglyceride content and is accompanied by mitochondrial dysfunction in the presence of compensatory oxidative phosphorylation (OXPHOS) complexes elevation. Our findings indicate that APOL1 risk variant expression increases the susceptibility to lipid-dependent podocyte injury, ultimately leading to mitochondrial dysfunction., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
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33. In the shadow of the pandemic.
- Author
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Dueña L, Varona J, Bereciartua E, and López L
- Published
- 2021
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34. Camera-Based Monitoring of Neck Movements for Cervical Rehabilitation Mobile Applications.
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Salinas-Bueno I, Roig-Maimó MF, Martínez-Bueso P, San-Sebastián-Fernández K, Varona J, and Mas-Sansó R
- Subjects
- Exercise Therapy, Head Movements, Humans, Neck, Range of Motion, Articular, Mobile Applications
- Abstract
Vision-based interfaces are used for monitoring human motion. In particular, camera-based head-trackers interpret the movement of the user's head for interacting with devices. Neck pain is one of the most important musculoskeletal conditions in prevalence and years lived with disability. A common treatment is therapeutic exercise, which requires high motivation and adherence to treatment. In this work, we conduct an exploratory experiment to validate the use of a non-invasive camera-based head-tracker monitoring neck movements. We do it by means of an exergame for performing the rehabilitation exercises using a mobile device. The experiments performed in order to explore its feasibility were: (1) validate neck's range of motion (ROM) that the camera-based head-tracker was able to detect; (2) ensure safety application in terms of neck ROM solicitation by the mobile application. Results not only confirmed safety, in terms of ROM requirements for different preset patient profiles, according with the safety parameters previously established, but also determined the effectiveness of the camera-based head-tracker to monitor the neck movements for rehabilitation purposes.
- Published
- 2021
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35. Crowdsourcing human-based computation for medical image analysis: A systematic literature review.
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Petrović N, Moyà-Alcover G, Varona J, and Jaume-I-Capó A
- Subjects
- Algorithms, Humans, Crowdsourcing
- Abstract
Computer-assisted algorithms for the analysis of medical images require human interactions to achieve satisfying results. Human-based computation and crowdsourcing offer a solution to this problem. We performed a systematic literature review of studies on crowdsourcing human-based computation for medical image analysis based on the guidelines proposed by Kitchenham and Charters. We identified 43 studies relevant to the objective of this research. We determined three primary purposes and problems that crowdsourcing human-based computation systems can solve. We found that the users provided five information types. We compared systems that use pre-, post-evaluation and quality control methods to select and filter the user inputs. We analyzed the metrics used for the evaluation of the crowdsourcing human-based computation system performance. Finally, we identified the most popular crowdsourcing human-based computation platforms with their advantages and disadvantages.Crowdsourcing human-based computation systems can successfully solve medical image analysis problems. However, the application of crowdsourcing human-based computation systems in this research area is still limited and more studies should be conducted to obtain generalizable results. We provided guidelines to practitioners and researchers based on the results obtained in this research.
- Published
- 2020
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36. Second week methyl-prednisolone pulses improve prognosis in patients with severe coronavirus disease 2019 pneumonia: An observational comparative study using routine care data.
- Author
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Ruiz-Irastorza G, Pijoan JI, Bereciartua E, Dunder S, Dominguez J, Garcia-Escudero P, Rodrigo A, Gomez-Carballo C, Varona J, Guio L, Ibarrola M, Ugarte A, and Martinez-Berriotxoa A
- Subjects
- Aged, COVID-19, Coronavirus Infections pathology, Female, Glucocorticoids therapeutic use, Humans, Inflammation, Intubation, Intratracheal, Male, Methylprednisolone pharmacology, Methylprednisolone therapeutic use, Middle Aged, Oxygen blood, Pandemics, Pneumonia, Viral pathology, Prognosis, Retrospective Studies, Risk, Risk Factors, Spain, Time Factors, Coronavirus Infections diagnosis, Methylprednisolone administration & dosage, Pneumonia, Viral diagnosis
- Abstract
Objective: To analyze the effects of a short course of methyl-prednisolone pulses (MP) during the second week of disease (week-2) in patients with severe coronavirus disease 2019 (COVID-19) pneumonia., Methods: Comparative observational study using data collected from routine care at Hospital Universitario Cruces, Barakaldo, Bizkaia, Spain in patients with COVID-19 pneumonia. We compared patients who received week-2-MP (125-250 mg/d x3) with those who did not, with the end-points time to death and time to death or endotracheal intubation., Results: We included 242 patients with COVID-19 pneumonia and elevated inflammatory markers at admission. Sixty-one patients (25%) received week-2-MP. Twenty-two patients (9%) died and 31 (12.8%) suffered death or intubation. The adjusted HRs for death and death or intubation for patients in the week-2-MP group were 0.35 (95%CI 0.11 to 1.06, p = 0.064) and 0.33 (95%CI 0.13 to 0.84, p = 0.020), respectively. These differences were specifically seen in the subcohort of patients with a SpO2/FiO2 at day 7 lower than 353 (adjusted HR 0.31, 95% CI 0.08 to 1.12, p = 0.073 and HR 0.34, 95%CI 0.12 to 0.94, p = 0.038, respectively) but not in patients with higher SpO2/FiO2. Patients receiving out-of-week-2-MP, non-pulse glucocorticoids or no glucocorticoids had an increased adjusted risk for both outcomes compared with week-2-MP group: HR 5.04 (95% CI 0.91-27.86), HR 10.09 (95% CI 2.14-47.50), HR 4.14 (95% CI 0.81-21.23), respectively, for death; HR 7.38 (95% CI 1.86-29.29), HR 13.71 (95% CI 3.76-50.07), HR 3.58 (95% CI 0.89-14.32), respectively, for death or intubation. These differences were significant only in the subgroup with low SpO2/FiO2., Conclusions: Week-2-MP are effective in improving the prognosis of patients with COVID-19 pneumonia with features of inflammatory activity and respiratory deterioration entering the second week of disease. The recognition of this high-risk population should prompt early use of MP at this point., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
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37. Vision-based serious games and virtual reality systems for motor rehabilitation: A review geared toward a research methodology.
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Ayed I, Ghazel A, Jaume-I-Capó A, Moyà-Alcover G, Varona J, and Martínez-Bueso P
- Subjects
- Humans, Upper Extremity physiopathology, Cerebral Palsy rehabilitation, Postural Balance, Psychomotor Performance, Research Design, Stroke Rehabilitation methods, Video Games, Virtual Reality
- Abstract
Background: Nowadays, information technologies are being widely adopted to promote healthcare and rehabilitation. Owing to their affordability and use of hand-free controllers, vision-based systems have gradually been integrated into motor rehabilitation programs and have greatly drawn the interest of healthcare practitioners and the research community. Many studies have illustrated the effectiveness of these systems in rehabilitation. However, the report and design aspects of the reported clinical trials were disregarded., Objective: In this paper, we present a systematic literature review of the use of vision-based serious games and virtual reality systems in motor rehabilitation programs. We aim to propose a research methodology that engineers can use to improve the designing and reporting processes of their clinical trials., Methods: We conducted a review of published studies that entail clinical experiments. Searches were performed using Web of Science and Medline (PubMed) electronic databases, and selected studies were assessed using the Downs and Black Checklist and then analyzed according to specific research questions., Results: We identified 86 studies and our findings indicate that the number of studies in this field is increasing, with Korea and USA in the lead. We found that Kinect, EyeToy system, and GestureTek IREX are the most commonly used technologies in studying the effects of vision-based serious games and virtual reality systems on rehabilitation. Findings also suggest that cerebral palsy and stroke patients are the main target groups, with a particular interest on the elderly patients in this target population. The findings indicate that most of the studies focused on postural control and upper extremity exercises and used different measurements during assessment., Conclusions: Although the research community's interest in this area is growing, many clinical trials lack sufficient clarity in many aspects and are not standardized. Some recommendations have been made throughout the article., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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38. Hydroxypropyl-β-cyclodextrin protects from kidney disease in experimental Alport syndrome and focal segmental glomerulosclerosis.
- Author
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Mitrofanova A, Molina J, Varona Santos J, Guzman J, Morales XA, Ducasa GM, Bryn J, Sloan A, Volosenco I, Kim JJ, Ge M, Mallela SK, Kretzler M, Eddy S, Martini S, Wahl P, Pastori S, Mendez AJ, Burke GW, Merscher S, and Fornoni A
- Subjects
- 2-Hydroxypropyl-beta-cyclodextrin pharmacology, Animals, Autoantigens genetics, Biopsy, Cholesterol metabolism, Collagen Type IV genetics, Doxorubicin toxicity, Female, Glomerulosclerosis, Focal Segmental chemically induced, Glomerulosclerosis, Focal Segmental metabolism, Glomerulosclerosis, Focal Segmental pathology, Humans, Lipid Metabolism drug effects, Mice, Mice, Knockout, Nephritis, Hereditary genetics, Nephritis, Hereditary metabolism, Nephritis, Hereditary pathology, Observational Studies as Topic, 2-Hydroxypropyl-beta-cyclodextrin therapeutic use, Glomerulosclerosis, Focal Segmental drug therapy, Kidney Glomerulus pathology, Nephritis, Hereditary drug therapy
- Abstract
Studies suggest that altered renal lipid metabolism plays a role in the pathogenesis of diabetic kidney disease and that genetic or pharmacological induction of cholesterol efflux protects from the development of diabetic kidney disease and focal segmental glomerulosclerosis (FSGS). Here we tested whether altered lipid metabolism contributes to renal failure in the Col4a3 knockout mouse model for Alport Syndrome. There was an eight-fold increase in the cholesterol content in renal cortexes of mice with Alport Syndrome. This was associated with increased glomerular lipid droplets and cholesterol crystals. Treatment of mice with Alport Syndrome with hydroxypropyl-β-cyclodextrin (HPβCD) reduced cholesterol content in the kidneys of mice with Alport Syndrome and protected from the development of albuminuria, renal failure, inflammation and tubulointerstitial fibrosis. Cholesterol efflux and trafficking-related genes were primarily affected in mice with Alport Syndrome and were differentially regulated in the kidney cortex and isolated glomeruli. HPβCD also protected from proteinuria and mesangial expansion in a second model of non-metabolic kidney disease, adriamycin-induced nephropathy. Consistent with our experimental findings, microarray analysis confirmed dysregulation of several lipid-related genes in glomeruli isolated from kidney biopsies of patients with primary FSGS enrolled in the NEPTUNE study. Thus, lipid dysmetabolism occurs in non-metabolic glomerular disorders such as Alport Syndrome and FSGS, and HPβCD improves renal function in experimental Alport Syndrome and FSGS., (Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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39. Feasibility of Kinect-Based Games for Balance Rehabilitation: A Case Study.
- Author
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Ayed I, Ghazel A, Jaume-I-Capó A, Moya-Alcover G, Varona J, and Martínez-Bueso P
- Subjects
- Aged, Feasibility Studies, Female, Games, Recreational, Humans, Patient Compliance, Rehabilitation methods, Treatment Outcome, Tunisia, Accidental Falls prevention & control, Postural Balance, Rehabilitation instrumentation, Video Games
- Abstract
We aimed at determining the effects of prototype games on older adults attending a rehabilitation program in an elderly house in this work. We conducted an initial case study where two participants underwent a 5-week intervention. Feasibility was assessed by examining recruitment, adherence, and safety. The Tinetti balance test was used as pretest and posttest assessments. Results show that adherence was very high and no adverse effects were registered during the sessions. The included participants also reported enjoyment during the playtime and exhibited improvements in Tinetti scores. The findings suggest that game-based rehabilitation can be useful for improving balance in elderly people and can be incorporated in a fall prevention program.
- Published
- 2018
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40. A Robust Camera-Based Interface for Mobile Entertainment.
- Author
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Roig-Maimó MF, Manresa-Yee C, and Varona J
- Abstract
Camera-based interfaces in mobile devices are starting to be used in games and apps, but few works have evaluated them in terms of usability or user perception. Due to the changing nature of mobile contexts, this evaluation requires extensive studies to consider the full spectrum of potential users and contexts. However, previous works usually evaluate these interfaces in controlled environments such as laboratory conditions, therefore, the findings cannot be generalized to real users and real contexts. In this work, we present a robust camera-based interface for mobile entertainment. The interface detects and tracks the user's head by processing the frames provided by the mobile device's front camera, and its position is then used to interact with the mobile apps. First, we evaluate the interface as a pointing device to study its accuracy, and different factors to configure such as the gain or the device's orientation, as well as the optimal target size for the interface. Second, we present an in the wild study to evaluate the usage and the user's perception when playing a game controlled by head motion. Finally, the game is published in an application store to make it available to a large number of potential users and contexts and we register usage data. Results show the feasibility of using this robust camera-based interface for mobile entertainment in different contexts and by different people.
- Published
- 2016
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41. Interactive rehabilitation system for improvement of balance therapies in people with cerebral palsy.
- Author
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Jaume-i-Capó A, Martínez-Bueso P, Moyà-Alcover B, and Varona J
- Subjects
- Adult, Aged, Algorithms, Exercise Therapy, Female, Functional Laterality physiology, Gait physiology, Games, Experimental, Humans, Male, Middle Aged, Monitoring, Physiologic, Motivation physiology, Posture physiology, Software, Treatment Outcome, Vestibular Function Tests, Video Games, Young Adult, Cerebral Palsy rehabilitation, Physical Therapy Modalities, Postural Balance physiology
- Abstract
The present study covers a new experimental system, designed to improve the balance and postural control of adults with cerebral palsy. This system is based on a serious game for balance rehabilitation therapy, designed using the prototype development paradigm and features for rehabilitation with serious games: feedback, adaptability, motivational elements, and monitoring. In addition, the employed interaction technology is based on computer vision because motor rehabilitation consists of body movements that can be recorded, and because vision capture technology is noninvasive and can be used for clients who have difficulties in holding physical devices. Previous research has indicated that serious games help to motivate clients in therapy sessions; however, there remains a paucity of clinical evidence involving functionality. We rigorously evaluated the effects of physiotherapy treatment on balance and gait function of adult subjects with cerebral palsy undergoing our experimental system. A 24-week physiotherapy intervention program was conducted with nine adults from a cerebral palsy center who exercised weekly in 20-min sessions. Findings demonstrated a significant increase in balance and gait function scores resulting in indicators of greater independence for our participating adults. Scores improved from 16 to 21 points in a scale of 28, according to the Tinetti Scale for risk of falls, moving from high fall risk to moderate fall risk. Our promising results indicate that our experimental system is feasible for balance rehabilitation therapy.
- Published
- 2014
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42. Improving vision-based motor rehabilitation interactive systems for users with disabilities using mirror feedback.
- Author
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Jaume-i-Capó A, Martínez-Bueso P, Moyà-Alcover B, and Varona J
- Subjects
- Acoustic Stimulation methods, Adult, Aged, Female, Humans, Male, Middle Aged, Young Adult, Cerebral Palsy rehabilitation, Persons with Disabilities rehabilitation, Feedback, Sensory, Psychomotor Performance, User-Computer Interface, Video Games
- Abstract
Observation is recommended in motor rehabilitation. For this reason, the aim of this study was to experimentally test the feasibility and benefit of including mirror feedback in vision-based rehabilitation systems: we projected the user on the screen. We conducted a user study by using a previously evaluated system that improved the balance and postural control of adults with cerebral palsy. We used a within-subjects design with the two defined feedback conditions (mirror and no-mirror) with two different groups of users (8 with disabilities and 32 without disabilities) using usability measures (time-to-start (T(s)) and time-to-complete (T(c))). A two-tailed paired samples t-test confirmed that in case of disabilities the mirror feedback facilitated the interaction in vision-based systems for rehabilitation. The measured times were significantly worse in the absence of the user's own visual feedback (T(s) = 7.09 (P < 0.001) and T(c) = 4.48 (P < 0.005)). In vision-based interaction systems, the input device is the user's own body; therefore, it makes sense that feedback should be related to the body of the user. In case of disabilities the mirror feedback mechanisms facilitated the interaction in vision-based systems for rehabilitation. Results recommends developers and researchers use this improvement in vision-based motor rehabilitation interactive systems.
- Published
- 2014
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43. Targeting of the Hedgehog signal transduction pathway suppresses survival of malignant pleural mesothelioma cells in vitro.
- Author
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You M, Varona-Santos J, Singh S, Robbins DJ, Savaraj N, and Nguyen DM
- Subjects
- Anilides pharmacology, Apoptosis drug effects, Arsenic Trioxide, Arsenicals pharmacology, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Dose-Response Relationship, Drug, Gene Expression Regulation, Neoplastic, Hedgehog Proteins genetics, Hedgehog Proteins metabolism, Humans, Itraconazole pharmacology, Lung Neoplasms genetics, Lung Neoplasms pathology, Mesothelioma genetics, Mesothelioma pathology, Mesothelioma, Malignant, Molecular Targeted Therapy, Oxides pharmacology, Pleural Neoplasms genetics, Pleural Neoplasms pathology, Pyridines pharmacology, Pyrimidines pharmacology, RNA Interference, Receptors, G-Protein-Coupled genetics, Receptors, G-Protein-Coupled metabolism, Smoothened Receptor, Time Factors, Transcription Factors genetics, Transcription Factors metabolism, Transfection, Zinc Finger Protein GLI1, Antineoplastic Agents pharmacology, Hedgehog Proteins antagonists & inhibitors, Lung Neoplasms metabolism, Mesothelioma metabolism, Pleural Neoplasms metabolism, Receptors, G-Protein-Coupled antagonists & inhibitors, Signal Transduction drug effects, Transcription Factors antagonists & inhibitors
- Abstract
Objective: The present study sought to determine whether the Hedgehog (Hh) pathway is active and regulates the cell growth of cultured malignant pleural mesothelioma (MPM) cells and to evaluate the efficacy of pathway blockade using smoothened (SMO) antagonists (SMO inhibitor GDC-0449 or the antifungal drug itraconazole [ITRA]) or Gli inhibitors (GANT61 or the antileukemia drug arsenic trioxide [ATO]) in suppressing MPM viability., Methods: Selective knockdown of SMO to inhibit Hh signaling was achieved by small interfering RNA in 3 representative MPM cells. The growth inhibitory effect of GDC-0449, ITRA, GANT61, and ATO was evaluated in 8 MPM lines, with cell viability quantified using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell death was determined by annexinV/propidium iodide staining and flow cytometry., Results: SMO small interfering RNA mediated a two- to more than fivefold reduction of SMO and Gli1 gene expression as determined by real-time quantitative reverse-transcriptase polymerase chain reaction, indicating significant Hh pathway blockade. This was associated with significantly reduced cell viability (34% ± 7% to 61% ± 14% of nontarget small interfering RNA controls; P = .0024 to P = .043). Treating MPM cells with Hh inhibitors resulted in a 1.5- to 4-fold reduction of Gli1 expression. These 4 Hh antagonists strongly suppressed MPM cell viability. More importantly, ITRA, ATO, GANT61 induced significant apoptosis in the representative MPM cells., Conclusions: Hh signaling is active in MPM and regulates cell viability. ATO and ITRA were as effective as the prototypic SMO inhibitor GDC-0449 and the Gli inhibitor GANT61 in suppressing Hh signaling in MPM cells. Pharmaceutical agents Food and Drug Administration-approved for other indications but recently found to have anti-Hh activity, such as ATO or ITRA, could be repurposed to treat MPM., (Copyright © 2014 The American Association for Thoracic Surgery. All rights reserved.)
- Published
- 2014
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44. TRAIL induces autophagic protein cleavage through caspase activation in melanoma cell lines under arginine deprivation.
- Author
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You M, Savaraj N, Kuo MT, Wangpaichitr M, Varona-Santos J, Wu C, Nguyen DM, and Feun L
- Subjects
- Apoptosis Regulatory Proteins metabolism, Arginine deficiency, Arginine metabolism, Autophagy-Related Protein 5, Beclin-1, Calpain antagonists & inhibitors, Caspase 10 metabolism, Caspase 3 metabolism, Caspase 6 metabolism, Caspase 8 metabolism, Caspase 9 metabolism, Caspase Inhibitors, Cell Line, Tumor, Enzyme Activation, Humans, Melanoma metabolism, Membrane Proteins metabolism, Microtubule-Associated Proteins metabolism, Apoptosis drug effects, Autophagy drug effects, Caspases metabolism, Hydrolases pharmacology, Melanoma drug therapy, Polyethylene Glycols pharmacology, TNF-Related Apoptosis-Inducing Ligand pharmacology
- Abstract
Arginine deprivation is a promising strategy for treating ASS-negative malignant tumors including melanoma. However, autophagy can potentially counteract the effectiveness of this treatment by acting as a pro-survival pathway. By combining tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) with arginine deprivation using ADI-PEG20 (pegylated arginine deiminase), we achieved enhanced apoptosis and accelerated cell death in melanoma cell lines. This implies a switch from autophagy to apoptosis. In our current investigation, we found that TRAIL could induce the cleavage of two key autophagic proteins, Beclin-1 and Atg5, in the combination treatment. Using specific inhibitors for individual caspases, we found that caspase-8 inhibitor could completely abolish the cleavage. Furthermore, caspase-8 inhibitor was able to fully reverse the enhanced cytotoxicity induced by TRAIL. Inhibitors for caspase-3, 6, 9, and 10 were able to block the cleavage of these two autophagic proteins to some extent and correspondingly rescue cells from the cytotoxicity of the combination of TRAIL and arginine deprivation. In contrast, calpain inhibitor could not prevent the cleavage of either Beclin-1 or Atg5, and was unable to prevent cell death. Overall, our data indicate that the cleavage of Beclin-1 and Atg5 by TRAIL-initiated caspase activation is one of the mechanisms that lead to the enhancement of the cytotoxicity in the combination treatment.
- Published
- 2013
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45. The combination of ADI-PEG20 and TRAIL effectively increases cell death in melanoma cell lines.
- Author
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You M, Savaraj N, Wangpaichitr M, Wu C, Kuo MT, Varona-Santos J, Nguyen DM, and Feun L
- Subjects
- Cell Line, Tumor, Humans, Proto-Oncogene Proteins c-bcl-2 metabolism, Antineoplastic Combined Chemotherapy Protocols, Apoptosis, Hydrolases therapeutic use, Melanoma drug therapy, Polyethylene Glycols therapeutic use, Skin Neoplasms drug therapy, TNF-Related Apoptosis-Inducing Ligand therapeutic use
- Abstract
Current treatment for advanced, metastatic melanoma is not very effective, and new modalities are needed. ADI-PEG20 is a drug that specifically targets ASS-negative malignant melanomas while sparing the ASS-expressing normal cells. Although laboratory research and clinical trials showed promising results, there are some ASS-negative cell lines and patients that can develop resistance to this drug. In this report, we combined ADI-PEG20 with another antitumor drug TRAIL to increase the killing of malignant melanoma cells. This combination can greatly inhibit cell growth (to over 80%) and also enhanced cell death (to over 60%) in four melanoma cell lines tested compared with control. We found that ADI-PEG20 could increase the cell surface receptors DR4/5 for TRAIL and that caspase activity correlated with the increased cell death. These two drugs could also increase the level of Noxa while decrease that of survivin. We propose that these two drugs can complement each other by activating the intrinsic and extrinsic apoptosis pathways, thus enhance the killing of melanoma cells., (Published by Elsevier Inc.)
- Published
- 2010
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46. Nephrin is expressed on the surface of insulin vesicles and facilitates glucose-stimulated insulin release.
- Author
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Fornoni A, Jeon J, Varona Santos J, Cobianchi L, Jauregui A, Inverardi L, Mandic SA, Bark C, Johnson K, McNamara G, Pileggi A, Molano RD, Reiser J, Tryggvason K, Kerjaschki D, Berggren PO, Mundel P, and Ricordi C
- Subjects
- Animals, Cell Membrane physiology, DNA Primers, Diabetes Mellitus, Experimental genetics, Diabetes Mellitus, Experimental immunology, Gene Expression Regulation, Humans, Insulin Secretion, Islets of Langerhans Transplantation, Mice, Polymerase Chain Reaction, RNA, Small Interfering genetics, Reference Values, Transfection, Transplantation, Heterologous, Diabetes Mellitus genetics, Glucose pharmacology, Insulin metabolism, Islets of Langerhans physiology, Membrane Proteins genetics
- Abstract
Objective: Nephrin, an immunoglobulin-like protein essential for the function of the glomerular podocyte and regulated in diabetic nephropathy, is also expressed in pancreatic beta-cells, where its function remains unknown. The aim of this study was to investigate whether diabetes modulates nephrin expression in human pancreatic islets and to explore the role of nephrin in beta-cell function., Research Design and Methods: Nephrin expression in human pancreas and in MIN6 insulinoma cells was studied by Western blot, PCR, confocal microscopy, subcellular fractionation, and immunogold labeling. Islets from diabetic (n = 5) and nondiabetic (n = 7) patients were compared. Stable transfection and siRNA knockdown in MIN-6 cells/human islets were used to study nephrin function in vitro and in vivo after transplantation in diabetic immunodeficient mice. Live imaging of green fluorescent protein (GFP)-nephrin-transfected cells was used to study nephrin endocytosis., Results: Nephrin was found at the plasma membrane and on insulin vesicles. Nephrin expression was decreased in islets from diabetic patients when compared with nondiabetic control subjects. Nephrin transfection in MIN-6 cells/pseudoislets resulted in higher glucose-stimulated insulin release in vitro and in vivo after transplantation into immunodeficient diabetic mice. Nephrin gene silencing abolished stimulated insulin release. Confocal imaging of GFP-nephrin-transfected cells revealed nephrin endocytosis upon glucose stimulation. Actin stabilization prevented nephrin trafficking as well as nephrin-positive effect on insulin release., Conclusions: Our data suggest that nephrin is an active component of insulin vesicle machinery that may affect vesicle-actin interaction and mobilization to the plasma membrane. Development of drugs targeting nephrin may represent a novel approach to treat diabetes.
- Published
- 2010
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47. Alignment-free prediction of polygalacturonases with pseudofolding topological indices: experimental isolation from Coffea arabica and prediction of a new sequence.
- Author
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Agüero-Chapin G, Varona-Santos J, de la Riva GA, Antunes A, González-Vlla T, Uriarte E, and González-Díaz H
- Subjects
- Polygalacturonase isolation & purification, Quantitative Structure-Activity Relationship, Coffea enzymology, Computer Simulation, Plant Proteins metabolism, Polygalacturonase metabolism, Protein Folding
- Abstract
Polygalacturonases (PGs) have called the attention of microbiology scientists and biotechnology or pharmaceutical industry because they are protein enzymes relevant to phytopathogens invasion, fruit ripening, and potential antimicrobial drug targets. Numeric Topological Indices (TIs) of protein pseudofolding lattices can be used as input for classification algorithms in Quantitative Structure-Activity Relationship (OSAR) studies. However, a comparative study of different OSAR models for PGs has not been reported. In this study, we calculated for the first time two classes of TIs (Spectral moments (pik) and Entropy (thetak) values) for the Markov matrices associated to pseudofolding lattices of 108 PGs and 100 non-PGs heterogeneous proteins. Afterward, we developed different linear classifiers based on Linear Discriminant Analysis (LDA) and four types of nonlinear Artificial Neural Networks (ANN). The pik-LDA model correctly classified 98.8% of PGs and 100% non-PGs used to train the model, as well as 98.1% of all sequences used as external validation series. The rk-LDA model was the more accurate and/or simpler found. In addition, we report for the first time the experimental isolation and successful prediction of a new PG sequence from Coffea arabica. This sequence was deposited in the GenBank by our group with accession number GDQ336394. The present type of models are an interesting alignment-free complement to alignment-based procedures.
- Published
- 2009
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48. 2D-RNA-coupling numbers: a new computational chemistry approach to link secondary structure topology with biological function.
- Author
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González-Díaz H, Agüero-Chapin G, Varona J, Molina R, Delogu G, Santana L, Uriarte E, and Podda G
- Subjects
- Algorithms, Amino Acid Oxidoreductases genetics, Amino Acid Oxidoreductases metabolism, Artificial Intelligence, Base Sequence, Coffea enzymology, Coffea genetics, Entropy, Logistic Models, Markov Chains, Plant Proteins chemistry, Plant Proteins genetics, Plant Proteins metabolism, RNA genetics, Static Electricity, Amino Acid Oxidoreductases chemistry, Computational Biology methods, Nucleic Acid Conformation, Quantitative Structure-Activity Relationship, RNA chemistry
- Abstract
Methods for prediction of proteins, DNA, or RNA function and mapping it onto sequence often rely on bioinformatics alignment approach instead of chemical structure. Consequently, it is interesting to develop computational chemistry approaches based on molecular descriptors. In this sense, many researchers used sequence-coupling numbers and our group extended them to 2D proteins representations. However, no coupling numbers have been reported for 2D-RNA topology graphs, which are highly branched and contain useful information. Here, we use a computational chemistry scheme: (a) transforming sequences into RNA secondary structures, (b) defining and calculating new 2D-RNA-coupling numbers, (c) seek a structure-function model, and (d) map biological function onto the folded RNA. We studied as example 1-aminocyclopropane-1-carboxylic acid (ACC) oxidases known as ACO, which control fruit ripening having importance for biotechnology industry. First, we calculated tau(k)(2D-RNA) values to a set of 90-folded RNAs, including 28 transcripts of ACO and control sequences. Afterwards, we compared the classification performance of 10 different classifiers implemented in the software WEKA. In particular, the logistic equation ACO = 23.8 . tau(1)(2D-RNA) + 41.4 predicts ACOs with 98.9%, 98.0%, and 97.8% of accuracy in training, leave-one-out and 10-fold cross-validation, respectively. Afterwards, with this equation we predict ACO function to a sequence isolated in this work from Coffea arabica (GenBank accession DQ218452). The tau(1)(2D-RNA) also favorably compare with other descriptors. This equation allows us to map the codification of ACO activity on different mRNA topology features. The present computational-chemistry approach is general and could be extended to connect RNA secondary structure topology to other functions.
- Published
- 2007
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49. Novel 2D maps and coupling numbers for protein sequences. The first QSAR study of polygalacturonases; isolation and prediction of a novel sequence from Psidium guajava L.
- Author
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Agüero-Chapin G, González-Díaz H, Molina R, Varona-Santos J, Uriarte E, and González-Díaz Y
- Subjects
- Amino Acid Sequence, Image Processing, Computer-Assisted, Molecular Sequence Data, Psidium enzymology, Algorithms, Plant Proteins genetics, Psidium genetics, Sequence Analysis, DNA, Software
- Abstract
The development of 2D graph-theoretic representations for DNA sequences was very important for qualitative and quantitative comparison of sequences. Calculation of numeric features for these representations is useful for DNA-QSAR studies. Most of all graph-theoretic representations identify each one of the four bases with a unitary walk in one axe direction in the 2D space. In the case of proteins, twenty amino acids instead of four bases have to be considered. This fact has limited the introduction of useful 2D Cartesian representations and the corresponding sequences descriptors to encode protein sequence information. In this study, we overcome this problem grouping amino acids into four groups: acid, basic, polar and non-polar amino acids. The identification of each group with one of the four axis directions determines a novel 2D representation and numeric descriptors for proteins sequences. Afterwards, a Markov model has been used to calculate new numeric descriptors of the protein sequence. These descriptors are called herein the sequence 2D coupling numbers (zeta(k)). In this work, we calculated the zeta(k) values for 108 sequences of different polygalacturonases (PGs) and for 100 sequences of other proteins. A Linear Discriminant Analysis model derived here (PG=5.36.zeta1-3.98.zeta3-42.21) successfully discriminates between PGs and other proteins. The model correctly classified 100% of a subset of 81 PGs and 75 non-PG proteins sequences used to train the model. The model also correctly classified 51 out of 52 (98.07%) of proteins sequences used as external validation series. The uses of different group of amino acids and/or axes orientation give different results, so it is suggested to be explored for other databases. Finally, to illustrates the use of the model we report the isolation and prediction of the PG action for a novel sequence (AY908988) isolated by our group from Psidium guajava L. This prediction coincides very well with sequence alignment results found by the BLAST methodology. These findings illustrate the possibilities of the sequence descriptors derived for this novel 2D sequence representation in proteins sequence QSAR studies.
- Published
- 2006
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50. 2D RNA-QSAR: assigning ACC oxidase family membership with stochastic molecular descriptors; isolation and prediction of a sequence from Psidium guajava L.
- Author
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González-Díaz H, Agüero-Chapin G, Varona-Santos J, Molina R, de la Riva G, and Uriarte E
- Subjects
- Models, Molecular, Quantitative Structure-Activity Relationship, Amino Acid Oxidoreductases chemistry, Amino Acid Oxidoreductases metabolism, Psidium enzymology, RNA chemistry
- Abstract
Quantitative structure-activity relationship (QSAR) techniques for small molecules could be applied to nucleic acids. Unfortunately, almost all molecular descriptors are more successful at encoding branching information than sequences and/or cannot be back-projected. A solution for scaling the QSAR problem up to RNA may be to transform sequences into secondary structures first. Our group has used Markovian negentropies as molecular descriptors for drug design with preliminary results in bioinformatics [Bioinformatics 2003, 19, 2079]. However, RNA-QSAR studies on RNA molecules have not been described to date. Novel Markovian negentropies have been introduced here as molecular descriptors for 2D-RNA structures. An RNA-QSAR study of the ACC proteins from different plants has been carried out. The QSAR recognizes 19/20 sequences (95.0%) within the ACC family and 12/17 (70.6%) of the control group sequences. The model has a high Matthews' regression coefficient (C = 0.68). Overall cross-validation average accuracies were 14 out of 15 for ACC sequences (93.3%) and 10 out of 13 for control sequences (76.9%). Finally, ACC oxidase family membership was assigned to a new sequence isolated for the first time in this work from Psidium guajava L. A backprojection map for this sequence identifies the left stem (40%) and the main stem (45%) as highly important substructures. Results of an nBLAST experiment are consistent with this finding and indicate a high conservation score (>70) for left stem and main stem; whereas major loop, right stem, cap and major loop right half were hardly conserved.
- Published
- 2005
- Full Text
- View/download PDF
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