13 results on '"Barrientos V"'
Search Results
2. Assessment of the effect of testosterone on the acrosome reaction of human spermatozoa
- Author
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Vigil, P., Barrientos, V. M., Vargas, G. G., Machuca, D. A., and Cortés, M. E.
- Published
- 2012
- Full Text
- View/download PDF
3. Injection of CO2-Saturated Water through a Siliceous Sandstone Plug from the Hontomin Test Site (Spain): Experiment and Modeling.
- Author
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Canal, J., Delgado, J., Falcón, I., Yang, Q., Juncosa, R., and Barrientos, V.
- Published
- 2013
- Full Text
- View/download PDF
4. Exogenous Volatile Organic Compound (EVOC ® ) Breath Testing Maximizes Classification Performance for Subjects with Cirrhosis and Reveals Signs of Portal Hypertension.
- Author
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Ferrandino G, Ricciardi F, Murgia A, Banda I, Manhota M, Ahmed Y, Sweeney K, Nicholson-Scott L, McConville L, Gandelman O, Allsworth M, Boyle B, Smolinska A, Ginesta Frings CA, Contreras J, Asenjo-Lobos C, Barrientos V, Clavo N, Novoa A, Riviotta A, Jerez M, and Méndez L
- Abstract
Background: Cirrhosis detection in primary care relies on low-performing biomarkers. Consequently, up to 75% of subjects with cirrhosis receive their first diagnosis with decompensation when causal treatments are less effective at preserving liver function. We investigated an unprecedented approach to cirrhosis detection based on dynamic breath testing. Methods: We enrolled 29 subjects with cirrhosis (Child-Pugh A and B), and 29 controls. All subjects fasted overnight. Breath samples were taken using Breath Biopsy
® before and at different time points after the administration of 100 mg limonene. Absolute limonene breath levels were measured using gas chromatography-mass spectrometry. Results: All subjects showed a >100-fold limonene spike in breath after administration compared to baseline. Limonene breath kinetics showed first-order decay in >90% of the participants, with higher bioavailability in the cirrhosis group. At the Youden index, baseline limonene levels showed classification performance with an area under the roc curve (AUROC) of 0.83 ± 0.012, sensitivity of 0.66 ± 0.09, and specificity of 0.83 ± 0.07. The best performing timepoint post-administration was 60 min, with an AUROC of 0.91, sensitivity of 0.83 ± 0.07, and specificity of 0.9 ± 0.06. In the cirrhosis group, limonene bioavailability showed a correlation with MELD and fibrosis indicators, and was associated with signs of portal hypertension. Conclusions: Dynamic limonene breath testing enhances diagnostic performance for cirrhosis compared to static testing. The correlation with disease severity suggests potential for monitoring therapeutic interventions. Given the non-invasive nature of breath collection, a dynamic limonene breath test could be implemented in primary care.- Published
- 2023
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5. Myeloid- and epithelial-derived RELMα contribute to tissue repair following lung helminth infection.
- Author
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Sveiven SN, Kim SY, Barrientos V, Li J, Jennett J, Asiedu S, Anesko K, Nordgren TM, and Nair MG
- Abstract
Soil-transmitted helminth (STH) infections impact billions of individuals globally; however, there is a need to clarify the long-term impacts of these infections on pulmonary health owing to their transient migration and subsequent damage to the lungs. In mouse models of these infections using Nippostrongylus brasiliensis , lung pathology persists at later time points post single infection. These studies also indicate the persistent transcriptional expression of resistin-like molecule α (RELMα), an immunomodulatory protein induced in type 2 immunity and alternatively activated macrophages. Using constitutive and tamoxifen-inducible cell-specific RELMα knockout mouse strains, we identified that epithelial- and myeloid-derived RELMα protein remained elevated at 30 days post infection and altered the immune cell signature and gene expression in lung compartments. Histopathological assessment of alveolar damage revealed a role for RELMα in tissue repair, suggesting the importance of sustained RELMα expression for lung recovery from helminth infection. Acellular three-dimensional (3D) lung scaffolds were prepared from the lungs of wild-type (WT), RELMα KO-naive, or 30 days post N . brasiliensis -infected mice to assess their ability to support epithelial cell growth. N . brasiliensis infection significantly altered the scaffold and impaired epithelial cell growth and metabolic activity, especially in the RELMα KO scaffolds. These findings underscore a need to identify the long-term impacts of helminth infection on human pulmonary disease, particularly as alveolar destruction can develop into chronic obstructive pulmonary disease (COPD), which remains among the top global causes of death. Translation of these findings to human protein resistin, with sequence homology to RELMα therapeutic opportunities in lung repair., Competing Interests: Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Published
- 2023
- Full Text
- View/download PDF
6. Glucocorticoids Decrease Longitudinal Bone Growth in Pediatric Kidney Transplant Recipients by Stimulating the FGF23/FGFR3 Signaling Pathway.
- Author
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Delucchi Á, Toro L, Alzamora R, Barrientos V, González M, Andaur R, León P, Villanueva F, Galindo M, Las Heras F, Montecino M, Moena D, Lazcano A, Pinto V, Salas P, Reyes ML, Mericq V, and Michea L
- Subjects
- Animals, Bone Density drug effects, Bone and Bones pathology, Child, Female, Fibroblast Growth Factor-23, Follow-Up Studies, Glucocorticoids adverse effects, Humans, Kidney Failure, Chronic metabolism, Kidney Failure, Chronic pathology, Kidney Failure, Chronic surgery, Klotho Proteins, Male, Membrane Proteins, Mice, Rats, Rats, Sprague-Dawley, Bone Development drug effects, Bone and Bones metabolism, Fibroblast Growth Factors metabolism, Glucocorticoids administration & dosage, Kidney Transplantation, Receptor, Fibroblast Growth Factor, Type 3 metabolism, Signal Transduction drug effects
- Abstract
Renal transplantation (RTx) is an effective therapy to improve clinical outcomes in pediatric patients with terminal chronic kidney disease. However, chronic immunosuppression with glucocorticoids (GCs) reduces bone growth and BMD. The mechanisms causing GC-induced growth impairment have not been fully clarified. Fibroblast growth factor 23 (FGF23) is a peptide hormone that regulates phosphate homeostasis and bone growth. In pathological conditions, FGF23 excess or abnormal FGF receptors (FGFR) activity leads to bone growth impairment. Experimental data indicate that FGF23 expression is induced by chronic GC exposure. Therefore, we hypothesize that GCs impair bone growth by increasing FGF23 expression, which has direct effects on bone growth plate. In a post hoc analysis of a multicentric randomized clinical trial of prepubertal RTx children treated with early GC withdrawal or chronic GC treatment, we observed that GC withdrawal was associated with improvement in longitudinal growth and BMD, and lower plasma FGF23 levels as compared with a chronic GC group. In prepubertal rats, GC-induced bone growth retardation correlated with increased plasma FGF23 and bone FGF23 expression. Additionally, GC treatment decreased FGFR1 expression whereas it increased FGFR3 expression in mouse tibia explants. The GC-induced bone growth impairment in tibiae explants was prevented by blockade of FGF23 receptors using either a pan-FGFR antagonist (PD173074), a C-terminal FGF23 peptide (FGF23180-205) which blocks the binding of FGF23 to the FGFR-Klotho complex or a specific FGFR3 antagonist (P3). Finally, local administration of PD173074 into the tibia growth plate ameliorated cartilage growth impairment in GC-treated rats. These results show that GC treatment partially reduces longitudinal bone growth via upregulation of FGF23 and FGFR3 expression, thus suggesting that the FGF23/Klotho/FGFR3 axis at the growth plate could be a potential therapeutic target for the management of GC-induced growth impairment in children., (© 2019 American Society for Bone and Mineral Research.)
- Published
- 2019
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7. Erythropoietin induces bone marrow and plasma fibroblast growth factor 23 during acute kidney injury.
- Author
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Toro L, Barrientos V, León P, Rojas M, Gonzalez M, González-Ibáñez A, Illanes S, Sugikawa K, Abarzúa N, Bascuñán C, Arcos K, Fuentealba C, Tong AM, Elorza AA, Pinto ME, Alzamora R, Romero C, and Michea L
- Subjects
- Acute Kidney Injury etiology, Animals, Bone Marrow Cells drug effects, Disease Models, Animal, Erythroid Precursor Cells drug effects, Erythropoietin pharmacology, Fibroblast Growth Factor-23, Humans, Male, Mice, Inbred C57BL, Prospective Studies, Rats, Sprague-Dawley, Receptors, Erythropoietin agonists, Receptors, Erythropoietin metabolism, Recombinant Proteins pharmacology, Sepsis blood, Sepsis complications, Shock, Hemorrhagic blood, Shock, Hemorrhagic complications, Time Factors, Up-Regulation, Acute Kidney Injury blood, Bone Marrow Cells metabolism, Erythroid Precursor Cells metabolism, Erythropoietin blood, Fibroblast Growth Factors blood
- Abstract
It is accepted that osteoblasts/osteocytes are the major source for circulating fibroblast growth factor 23 (FGF23). However, erythropoietic cells of bone marrow also express FGF23. The modulation of FGF23 expression in bone marrow and potential contribution to circulating FGF23 has not been well studied. Moreover, recent studies show that plasma FGF23 may increase early during acute kidney injury (AKI). Erythropoietin, a kidney-derived hormone that targets erythropoietic cells, increases in AKI. Here we tested whether an acute increase of plasma erythropoietin induces FGF23 expression in erythropoietic cells of bone marrow thereby contributing to the increase of circulating FGF23 in AKI. We found that erythroid progenitor cells of bone marrow express FGF23. Erythropoietin increased FGF23 expression in vivo and in bone marrow cell cultures via the homodimeric erythropoietin receptor. In experimental AKI secondary to hemorrhagic shock or sepsis in rodents, there was a rapid increase of plasma erythropoietin, and an induction of bone marrow FGF23 expression together with a rapid increase of circulating FGF23. Blockade of the erythropoietin receptor fully prevented the induction of bone marrow FGF23 and partially suppressed the increase of circulating FGF23. Finally, there was an early increase of both circulating FGF23 and erythropoietin in a cohort of patients with severe sepsis who developed AKI within 48 hours of admission. Thus, increases in plasma erythropoietin and erythropoietin receptor activation are mechanisms implicated in the increase of plasma FGF23 in AKI., (Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
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8. Mineralocorticoids modulate the expression of the β-3 subunit of the Na + , K + -ATPase in the renal collecting duct.
- Author
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Rojas M, Díaz P, León P, Gonzalez AA, González M, Barrientos V, Pestov NB, Alzamora R, and Michea L
- Subjects
- Aldosterone pharmacology, Animals, Cell Line, Cell Membrane metabolism, Epithelial Sodium Channel Agonists pharmacology, Epithelial Sodium Channels metabolism, Male, Rats, Sprague-Dawley, Kidney Tubules metabolism, Mineralocorticoids pharmacology, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Renal sodium reabsorption depends on the activity of the Na
+ ,K+ -ATPase α/β heterodimer. Four α (α1-4 ) and 3 β (β1-3 ) subunit isoforms have been described. It is accepted that renal tubule cells express α1 /β1 dimers. Aldosterone stimulates Na+ ,K+ -ATPase activity and may modulate α1 /β1 expression. However, some studies suggest the presence of β3 in the kidney. We hypothesized that the β3 isoform of the Na+ ,K+ -ATPase is expressed in tubular cells of the distal nephron, and modulated by mineralocorticoids. We found that β3 is highly expressed in collecting duct of rodents, and that mineralocorticoids decreased the expression of β3 . Thus, we describe a novel molecular mechanism of sodium pump modulation that may contribute to the effects of mineralocorticoids on sodium reabsorption.- Published
- 2017
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9. Spironolactone decreases DOCA-salt-induced organ damage by blocking the activation of T helper 17 and the downregulation of regulatory T lymphocytes.
- Author
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Amador CA, Barrientos V, Peña J, Herrada AA, González M, Valdés S, Carrasco L, Alzamora R, Figueroa F, Kalergis AM, and Michea L
- Subjects
- Animals, Antibodies immunology, Antibodies pharmacology, Desoxycorticosterone Acetate pharmacology, Disease Models, Animal, Down-Regulation drug effects, Down-Regulation physiology, Forkhead Transcription Factors drug effects, Forkhead Transcription Factors physiology, Heart Diseases etiology, Heart Diseases physiopathology, Hypertension complications, Hypertension physiopathology, Interleukin-17 antagonists & inhibitors, Interleukin-17 immunology, Interleukin-17 physiology, Kidney Diseases etiology, Kidney Diseases physiopathology, Male, Mineralocorticoid Receptor Antagonists pharmacology, Rats, Rats, Sprague-Dawley, Receptors, Mineralocorticoid drug effects, Receptors, Mineralocorticoid physiology, Signal Transduction drug effects, Signal Transduction physiology, T-Lymphocytes, Regulatory pathology, Th17 Cells pathology, Desoxycorticosterone Acetate adverse effects, Heart Diseases prevention & control, Hypertension chemically induced, Kidney Diseases prevention & control, Spironolactone pharmacology, T-Lymphocytes, Regulatory drug effects, Th17 Cells drug effects
- Abstract
Adaptive immune response has been implicated in inflammation and fibrosis as a result of exposure to mineralocorticoids and a high-salt diet. We hypothesized that in mineralocorticoid-salt-induced hypertension, activation of the mineralocorticoid receptor alters the T-helper 17 lymphocyte (Th17)/regulatory T-lymphocyte/interleukin-17 (IL-17) pathway, contributing to cardiac and renal damage. We studied the inflammatory response and tissue damage in rats treated with deoxycorticosterone acetate and high-salt diet (DOCA-salt), with or without mineralocorticoid receptor inhibition by spironolactone. To determine whether Th17 differentiation in DOCA-salt rats is caused by hypertension per se, DOCA-salt rats received antihypertensive therapy. In addition, to evaluate the pathogenic role of IL-17 in hypertension and tissue damage, we studied the effect of IL-17 blockade with a specific antibody (anti-IL-17). We found activation of Th17 cells and downregulation of forkhead box P3 mRNA in peripheral tissues, heart, and kidneys of DOCA-salt-treated rats. Spironolactone treatment prevented Th17 cell activation and increased numbers of forkhead box P3-positive cells relative to DOCA-salt rats. Antihypertensive therapy did not ameliorate Th17 activation in rats. Treatment of DOCA-salt rats with anti-IL-17 significantly reduced arterial hypertension as well as expression of profibrotic and proinflammatory mediators and collagen deposits in the heart and kidney. We conclude that mineralocorticoid receptor activation alters the Th17/regulatory T-lymphocyte/IL-17 pathway in mineralocorticoid-dependent hypertension as part of an inflammatory mechanism contributing to fibrosis.
- Published
- 2014
- Full Text
- View/download PDF
10. Angiotensin-(1-9) reverses experimental hypertension and cardiovascular damage by inhibition of the angiotensin converting enzyme/Ang II axis.
- Author
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Ocaranza MP, Moya J, Barrientos V, Alzamora R, Hevia D, Morales C, Pinto M, Escudero N, García L, Novoa U, Ayala P, Díaz-Araya G, Godoy I, Chiong M, Lavandero S, Jalil JE, and Michea L
- Subjects
- Angiotensin II Type 1 Receptor Blockers chemistry, Animals, Aorta pathology, Blood Pressure drug effects, Cardiovascular Diseases prevention & control, Disease Models, Animal, Echocardiography, Endothelium, Vascular pathology, Heart Ventricles, Hemodynamics, Hypertension physiopathology, Imidazoles chemistry, Male, Oxidative Stress, Pyridines chemistry, Rats, Rats, Sprague-Dawley, Angiotensin I chemistry, Angiotensin II chemistry, Angiotensin-Converting Enzyme Inhibitors chemistry, Cardiovascular Diseases drug therapy, Hypertension drug therapy, Peptide Fragments chemistry
- Abstract
Background: Little is known about the biological effects of angiotensin-(1-9), but available evidence shows that angiotensin-(1-9) has beneficial effects in preventing/ameliorating cardiovascular remodeling., Objective: In this study, we evaluated whether angiotensin-(1-9) decreases hypertension and reverses experimental cardiovascular damage in the rat., Methods and Results: Angiotensin-(1-9) (600 ng/kg per min for 2 weeks) reduced already-established hypertension in rats with early high blood pressure induced by angiotensin II infusion or renal artery clipping. Angiotensin-(1-9) also improved cardiac (assessed by echocardiography) and endothelial function in small-diameter mesenteric arteries, cardiac and aortic wall hypertrophy, fibrosis, oxidative stress, collagen and transforming growth factor type β - 1 protein expression (assessed by western blot). The beneficial effect of angiotensin-(1-9) was blunted by coadministration of the angiotensin type 2(AT2) receptor blocker PD123319 (36 ng/kg per min) but not by coadministration of the Mas receptor blocker A779 (100 ng/kg per min). Angiotensin-(1-9) treatment also decreased circulating levels of Ang II, angiotensin-converting enzyme activity and oxidative stress in aorta and left ventricle. Whereas, Ang-(1-9) increased endothelial nitric oxide synthase mRNA levels in aorta as well as plasma nitrate levels., Conclusion: Angiotensin-(1-9) reduces hypertension, ameliorates structural alterations (hypertrophy and fibrosis), oxidative stress in the heart and aorta and improves cardiac and endothelial function in hypertensive rats. These effects were mediated by the AT2 receptor but not by the angiotensin-(1-7)/Mas receptor axis.
- Published
- 2014
- Full Text
- View/download PDF
11. Injection of CO2-saturated water through a siliceous sandstone plug from the Hontomin test site (Spain): experiment and modeling.
- Author
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Canal J, Delgado J, Falcón I, Yang Q, Juncosa R, and Barrientos V
- Subjects
- Carbon Sequestration, Spain, Water chemistry, Carbon Dioxide chemistry, Minerals chemistry, Models, Theoretical
- Abstract
Massive chemical reactions are not expected when injecting CO(2) in siliceous sandstone reservoirs, but their performance can be challenged by small-scale reactions and other processes affecting their transport properties. We have conducted a core flooding test with a quartzarenite plug of Lower Cretaceous age representative of the secondary reservoir of the Hontomín test site. The sample, confined at high pressure, was successively injected with DIW and CO(2)-saturated DIW for 49 days while monitoring geophysical, chemical, and hydrodynamic parameters. The plug experienced little change, without evidence of secondary carbonation. However, permeability increased by a factor of 4 (0.022-0.085 mD), and the V(P)/V(S) ratio, whose change is related with microcracking, rose from ~1.68 to ~1.8. Porosity also increased (7.33-8.1%) from the beginning to the end of the experiment. Fluid/rock reactions were modeled with PHREEQC-2, and they are dominated by the dissolution of Mg-calcite. Mass balances show that ~4% of the initial carbonate was consumed. The results suggest that mineral dissolution and microcracking may have acted in a synergistic way at the beginning of the acidic flooding. However, dissolution processes concentrated in pore throats can better explain the permeability enhancement observed over longer periods of time.
- Published
- 2013
- Full Text
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12. Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.
- Author
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González A, Labrín N, Alvarez RM, Jayaro Y, Gamboa C, Reyes E, and Barrientos V
- Subjects
- Animals, Antibiosis physiology, Genotype, Oryza genetics, Venezuela, Hemiptera physiology, Host-Parasite Interactions, Oryza parasitology
- Abstract
Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata.
- Published
- 2012
13. Modification of the official AOAC method for fat content determination of dried egg yolk.
- Author
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Navarro JG, Borie F, Barrientos V, and Caiozzi M
- Subjects
- Chromatography, Gas, Evaluation Studies as Topic, Fatty Acids analysis, Female, Food Preservation, Methods, Societies, Scientific, Egg Yolk analysis, Lipids analysis
- Published
- 1971
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