32 results on '"VALENZUELA R"'
Search Results
2. Estrogen and angiotensin interaction in the substantia nigra. Relevance to postmenopausal Parkinson's disease
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Rodriguez-Perez, A.I. (Ana I.), Valenzuela, R. (Rita), Villar, B. (Begoña), Guerra, M.J. (M. J.), Lanciego, J.L. (José Luis), and Labandeira-Garcia, J.L. (José L.)
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Angiotensin ,nervous system ,Neuroinflammation ,Dopamine ,NADPH ,Parkinson ,Menopause ,Replacement therapy ,Estrogen ,hormones, hormone substitutes, and hormone antagonists ,Neuroprotection - Abstract
Epidemiological studies have reported that the incidence of Parkinson's disease (PD) is higher in postmenopausal than in premenopausal women of similar age. Several laboratory observations have revealed that estrogen has protective effects against dopaminergic toxins. The mechanism by which estrogen protects dopaminergic neurons has not been clarified, although estrogen-induced attenuation of the neuroinflammatory response plays a major role. We have recently shown that activation of the nigral renin-angiotensin system (RAS), via type 1 (AT1) receptors, leads to NADPH complex and microglial activation and induces dopaminergic neuron death. In the present study we investigated the effect of ovariectomy and estrogen replacement on the nigral RAS and on dopaminergic degeneration induced by intrastriatal injection of 6-OHDA. We observed a marked loss of dopaminergic neurons in ovariectomized rats treated with 6-OHDA, which was significantly reduced by estrogen replacement or treatment with the AT1 receptor antagonist candesartan. We also observed that estrogen replacement induces significant downregulation of the activity of the angiotensin converting enzyme as well as downregulation of AT1 receptors, upregulation of AT2 receptors and downregulation of the NADPH complex activity in the substantia nigra in comparison with ovariectomized rats. The present results suggest that estrogen-induced down-regulation of RAS and NADPH activity may be associated with the reduced risk of PD in premenopausal women, and increased risk in conditions causing early reduction in endogenous estrogen, and that manipulation of brain RAS system may be an efficient approach for the prevention or coadjutant treatment of PD in estrogen-deficient women.
- Published
- 2010
3. Magnetic Energy Density and Friction Factor in Magnetic Amorphous Ribbons
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MAGAÑA, L.F., primary and VALENZUELA, R., additional
- Published
- 1988
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4. Study of a SOFC with a bimetallic Cu-Co-ceria anode directly fuelled with simulated biogas mixtures
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Comunidad de Madrid, Ministerio de Economía y Competitividad (España), Fuerte, Araceli, Valenzuela, R. X., Escudero, María José, Daza Bertrand, Loreto, Comunidad de Madrid, Ministerio de Economía y Competitividad (España), Fuerte, Araceli, Valenzuela, R. X., Escudero, María José, and Daza Bertrand, Loreto
- Abstract
The present work is focused in the study of the bimetallic Cu–Co formulation combined with CeO2 as SOFC anode, at 750 °C, direct feed of methane and two different fuel mixtures that simulate biogas. Additionally, the sulphur tolerance of new anode material has been evaluated. Its single cell evaluation, based on a samaria doped ceria (SDC) solid electrolyte and a LSM perovskite cathode, together with the electrochemical characterisation and catalytic activity tests, have allowed to demonstrate the ability of this material to operate directly with simulated biogas mixtures without loss of single cell performance due to the formation of carbon deposits or sulphur anode poisoning. The activity of this material for the exothermic oxidation of methane reduces the energy requirement of the endothermic internal methane reforming process. The cobalt doping of basic copper–ceria formulation enhanced sulphur and carbon coking tolerance of the SOFC anode material.
- Published
- 2014
5. Specific activity of mouse liver desaturases and elongases: Time course effects using n-3 and n-6 PUFA substrates and inhibitory responses of delta-6 desaturase.
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Valenzuela R, Metherel AH, Cisbani G, Smith ME, Chouinard-Watkins R, Klievik BJ, Farias C, Videla LA, and Bazinet RP
- Abstract
The synthesis of n-3 and n-6 polyunsaturated acids (PUFAs) is associated with physiological functions in mammals, being catalyzed by Δ-5D and Δ-6D desaturases and elongases Elovl-2 and Elovl-5. In this context, we aimed to study the chief kinetic features of PUFA liver anabolism, looking upon (i) the time-dependency for the specific activity of Δ-6D, Δ-5D, Elovl2, Elovl2/5 and Elovl5, using n-3 and n-6 precursors between 0 and 240 min ex vivo in mouse liver.; and (ii) the specific activity-substrate (α-linolenic acid; ALA) concentration responses of Δ-6D in the absence and presence of linoleic acid (LA), arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), an enzyme regarded as the rate-limiting step in PUFA anabolism. Mouse liver was obtained from eight-week-old Balb/c mice fed a chow diet (expressed as % of total calories: 18 % fat, 24 % protein, and 58 % carbohydrate, with a caloric value of 3.1 kcal/g) for eight weeks, and used for preparation of the microsomal fraction. Enzymatic activities assayed under the addition of specific PUFA precursors or LA, ARA, EPA and DHA, identifying the respective PUFA products as fatty acid methyl esters by gas chromatographic analysis. Data described corroborate that (i) PUFA metabolism mainly occurs in the liver, with the participating enzymes preferring n-3 than n-6 substrates; and show that (ii) the rate-limiting step of PUFA metabolism relies on the second reaction of Δ-6D (24:5n-3 transformed to 24:6n-3); and (iii) LA, ARA, EPA and DHA act as non-competitive inhibitors with respect to ALA in the reaction catalyzed by Δ-6D. These results are relevant for future studies concerning the metabolic and nutritional implications of changes in desaturation and elongation of PUFAs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier B.V.)
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- 2025
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6. Efficacy and safety of withholding antimicrobial therapy in children with cancer, fever, and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial.
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Torres JP, Ibañez C, Valenzuela R, Rivera S, De la Maza V, Villarroel M, Coria P, Contardo V, Álvarez AM, Zubieta CM, Gutierrez V, Ducasse K, Martínez D, and Santolaya ME
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- Humans, Male, Female, Child, Child, Preschool, Prospective Studies, Chile, Febrile Neutropenia drug therapy, Infant, Withholding Treatment, Fever drug therapy, Treatment Outcome, Anti-Infective Agents therapeutic use, Anti-Infective Agents administration & dosage, Anti-Infective Agents adverse effects, Anti-Bacterial Agents therapeutic use, Anti-Bacterial Agents administration & dosage, Anti-Bacterial Agents adverse effects, Hospitalization, Adolescent, Respiratory Tract Infections drug therapy, Respiratory Tract Infections virology, Virus Diseases drug therapy, Neoplasms drug therapy, Neoplasms complications
- Abstract
Objectives: To validate the efficacy and safety of withholding antimicrobial therapy in a new cohort of children with cancer and febrile neutropenia (FN) having a demonstrated viral respiratory tract infection., Methods: Prospective, multicenter, noninferiority, randomized study, approved by the ethical committee, in children presenting with FN at seven hospitals in Chile, evaluated at admission for diagnosis of bacterial and viral pathogens. Children who were positive for a respiratory virus, negative for a bacterial pathogen, and had a favourable evolution after 48-72 hours of antimicrobial therapy were randomized to either maintain or withhold antimicrobial therapy. The primary endpoint was the percentage of episodes with an uneventful resolution, whereas the secondary endpoints were days of fever, days of hospitalization, requirement of antimicrobial treatment readministration, sepsis, paediatric intensive care unit admission, and death., Results: A total of 301 of 939 children with FN episodes recruited between March 2021 and December 2023 had a respiratory virus as a unique identified microorganism, of which 139 had a favourable evolution at 48-72 hours and were randomized, 70 to maintain and 69 to withdraw antimicrobial therapy. The median days of antimicrobial therapy was 5 (IQR 3-6) versus 3 (IQR 3-6) days (p < 0.001), with similar frequency of uneventful resolution 66/70 (94%) and 66/69 (96%); relative risk, 1.01; (95% CI, 0.93 to 1.09), absolute risk difference 0.01; (95% CI, -0.05 to 0.08) and similar number of days of fever and days of hospitalization. No cases of sepsis, paediatric intensive care unit admission, or death were reported., Discussion: We validated the strategy of withdrawal antimicrobial therapy in children with FN and viral respiratory tract infection based on clinical and microbiological/molecular diagnostic criteria. This will enable advances in antimicrobial stewardship strategies with a possible future impact on antimicrobial resistance., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
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7. Dietary docosahexaenoic acid (DHA) downregulates liver DHA synthesis by inhibiting eicosapentaenoic acid elongation.
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Metherel AH, Valenzuela R, Klievik BJ, Cisbani G, Rotarescu RD, Gonzalez-Soto M, Cruciani-Guglielmacci C, Layé S, Magnan C, Mutch DM, and Bazinet RP
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- Animals, Mice, Male, Mice, Inbred C57BL, alpha-Linolenic Acid pharmacology, alpha-Linolenic Acid metabolism, alpha-Linolenic Acid administration & dosage, Docosahexaenoic Acids pharmacology, Docosahexaenoic Acids metabolism, Docosahexaenoic Acids administration & dosage, Eicosapentaenoic Acid pharmacology, Eicosapentaenoic Acid metabolism, Liver metabolism, Liver drug effects, Down-Regulation drug effects
- Abstract
DHA is abundant in the brain where it regulates cell survival, neurogenesis, and neuroinflammation. DHA can be obtained from the diet or synthesized from alpha-linolenic acid (ALA; 18:3n-3) via a series of desaturation and elongation reactions occurring in the liver. Tracer studies suggest that dietary DHA can downregulate its own synthesis, but the mechanism remains undetermined and is the primary objective of this manuscript. First, we show by tracing
13 C content (δ13 C) of DHA via compound-specific isotope analysis, that following low dietary DHA, the brain receives DHA synthesized from ALA. We then show that dietary DHA increases mouse liver and serum EPA, which is dependant on ALA. Furthermore, by compound-specific isotope analysis we demonstrate that the source of increased EPA is slowed EPA metabolism, not increased DHA retroconversion as previously assumed. DHA feeding alone or with ALA lowered liver elongation of very long chain (ELOVL2, EPA elongation) enzyme activity despite no change in protein content. To further evaluate the role of ELOVL2, a liver-specific Elovl2 KO was generated showing that DHA feeding in the presence or absence of a functional liver ELOVL2 yields similar results. An enzyme competition assay for EPA elongation suggests both uncompetitive and noncompetitive inhibition by DHA depending on DHA levels. To translate our findings, we show that DHA supplementation in men and women increases EPA levels in a manner dependent on a SNP (rs953413) in the ELOVL2 gene. In conclusion, we identify a novel feedback inhibition pathway where dietary DHA downregulates its liver synthesis by inhibiting EPA elongation., Competing Interests: Conflict of interest D. M. M. has received research grants from the Canola Council of Canada and the Dairy Farmers of Canada. R. P. B. has received industrial grants, including those matched by the Canadian government, and/or travel support related to work on brain fatty acid uptake from Arctic Nutrition, Bunge Ltd, DSM, Fonterra, Mead Johnson, and Nestle, Inc. Moreover, R. P. B. is on the executive of the International Society for the Study of Fatty Acids and Lipids and held a meeting on behalf of Fatty Acids and Cell Signaling, both of which rely on corporate sponsorship. R. P. B. has given expert testimony in relation to supplements and the brain and holds the Canada Research Chair in Brain Lipid Metabolism. A. H. M. is a board member of the ISSFAL. None of the other authors report a conflict of interest related to research presented in this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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8. Comparative study of droplet-digital PCR and absolute Q digital PCR for ctDNA detection in early-stage breast cancer patients.
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Sánchez-Martín V, López-López E, Reguero-Paredes D, Godoy-Ortiz A, Domínguez-Recio ME, Jiménez-Rodríguez B, Alba-Bernal A, Elena Quirós-Ortega M, Roldán-Díaz MD, Velasco-Suelto J, Linares-Valencia N, Garrido-Aranda A, Lavado-Valenzuela R, Álvarez M, Pascual J, Alba E, and Comino-Méndez I
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- Humans, Biomarkers, Tumor genetics, Mutation, Polymerase Chain Reaction methods, Cell-Free Nucleic Acids, Circulating Tumor DNA genetics, Triple Negative Breast Neoplasms
- Abstract
Background: Analysis of circulating tumor DNA (ctDNA) is increasingly used for clinical decision-making in oncology. However, ctDNA could represent ≤ 0.1 % of cell-free DNA in early-stage tumors and its detection requires high-sensitive techniques such as digital PCR (dPCR)., Methods: In 46 samples from patients with early-stage breast cancer, we compared two leading dPCR assays for ctDNA analysis: QX200 droplet digital PCR (ddPCR) system from Bio-Rad which is the gold-standard in the field, and Absolute Q plate-based digital PCR (pdPCR) system from Thermo Fisher Scientific which has not been reported before. We analyzed 5 mL of baseline plasma samples prior to any treatment., Results: Both systems displayed a comparable sensitivity with no significant differences observed in mutant allele frequency. In fact, ddPCR and pdPCR possessed a concordance > 90 % in ctDNA positivity. Nevertheless, ddPCR exhibited higher variability and a longer workflow. Finally, we explored the association between ctDNA levels and clinicopathological features. Significantly higher ctDNA levels were present in patients with a Ki67 score > 20 % or with estrogen receptor-negative or triple-negative breast cancer subtypes., Conclusion: Both ddPCR and pdPCR may constitute sensitive and reliable tools for ctDNA analysis with an adequate agreement in early-stage breast cancer patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
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9. Novel 13 C enrichment technique reveals early turnover of DHA in peripheral tissues.
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Klievik BJ, Metherel AH, Cisbani G, Valenzuela R, and Bazinet RP
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- Mice, Animals, Isotopes, Liver, Docosahexaenoic Acids chemistry, Diet
- Abstract
The brain is rich in DHA, which plays important roles in regulating neuronal function. Recently, using compound-specific isotope analysis that takes advantage of natural differences in carbon-13 content (
13 C/12 C ratio or δ13 C) of the food supply, we determined the brain DHA half-life. However, because of methodological limitations, we were unable to capture DHA turnover rates in peripheral tissues. In the current study, we applied compound-specific isotope analysis via high-precision GC combustion isotope ratio mass spectrometry to determine half-lives of brain, liver, and plasma DHA in mice following a dietary switch experiment. To model DHA tissue turnover rates in peripheral tissues, we added earlier time points within the diet switch study and took advantage of natural variations in the δ13 C-DHA of algal and fish DHA sources to maintain DHA pool sizes and used an enriched (uniformly labeled13 C) DHA treatment. Mice were fed a fish-DHA diet (control) for 3 months, then switched to an algal-DHA treatment diet, the13 C enriched-DHA treatment diet, or they stayed on the control diet for the remainder of the study time course. In mice fed the algal and13 C enriched-DHA diets, the brain DHA half-life was 47 and 46 days, the liver half-life was 5.6 and 7.2 days, and the plasma half-life was 4.7 and 6.4 days, respectively. By using improved methodologies, we calculated DHA turnover rates in the liver and plasma, and our study for the first time, by using an enriched DHA source (very high δ13 C), validated its utility in diet switch studies., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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10. AT1 receptor autoantibodies mediate effects of metabolic syndrome on dopaminergic vulnerability.
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Pedrosa MA, Labandeira CM, Valenzuela R, Quijano A, Sanchez-Andrade M, Suarez-Quintanilla JA, Lanciego JL, Labandeira-Garcia JL, and Rodriguez-Perez AI
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- Animals, Humans, Rats, Angiotensin II metabolism, Angiotensin II pharmacology, Angiotensin Receptor Antagonists metabolism, Angiotensin Receptor Antagonists pharmacology, Angiotensin-Converting Enzyme 2 metabolism, Angiotensin-Converting Enzyme Inhibitors metabolism, Angiotensin-Converting Enzyme Inhibitors pharmacology, Autoantibodies metabolism, Dopamine metabolism, Dopaminergic Neurons metabolism, Endothelial Cells metabolism, Inflammation metabolism, Neuroinflammatory Diseases, Receptor, Angiotensin, Type 1 metabolism, Metabolic Syndrome metabolism, Parkinson Disease metabolism
- Abstract
The metabolic syndrome has been associated to chronic peripheral inflammation and related with neuroinflammation and neurodegeneration, including Parkinson's disease. However, the responsible mechanisms are unclear. Previous studies have involved the brain renin-angiotensin system in progression of Parkinson's disease and the angiotensin receptor type 1 (AT1) has been recently revealed as a major marker of dopaminergic vulnerability in humans. Dysregulation of tissue renin-angiotensin system is a key common mechanism for all major components of metabolic syndrome. Circulating AT1 agonistic autoantibodies have been observed in several inflammation-related peripheral processes, and activation of AT1 receptors of endothelial cells, dopaminergic neurons and glial cells have been observed to disrupt endothelial blood -brain barrier and induce neurodegeneration, respectively. Using a rat model, we observed that metabolic syndrome induces overactivity of nigral pro-inflammatory renin-angiotensin system axis, leading to increase in oxidative stress and neuroinflammation and enhancing dopaminergic neurodegeneration, which was inhibited by treatment with AT1 receptor blockers (ARBs). In rats, metabolic syndrome induced the increase in circulating levels of LIGHT and other major pro-inflammatory cytokines, and 27-hydroxycholesterol. Furthermore, the rats showed a significant increase in serum levels of proinflammatory AT1 and angiotensin converting enzyme 2 (ACE2) autoantibodies, which correlated with levels of several metabolic syndrome parameters. We also found AT1 and ACE2 autoantibodies in the CSF of these rats. Effects of circulating autoantibodies were confirmed by chronic infusion of AT1 autoantibodies, which induced blood-brain barrier disruption, an increase in the pro-inflammatory renin-angiotensin system activity in the substantia nigra and a significant enhancement in dopaminergic neuron death in two different rat models of Parkinson's disease. Observations in the rat models, were analyzed in a cohort of parkinsonian and non-parkinsonian patients with or without metabolic syndrome. Non-parkinsonian patients with metabolic syndrome showed significantly higher levels of AT1 autoantibodies than non-parkinsonian patients without metabolic syndrome. However, there was no significant difference between parkinsonian patients with metabolic syndrome or without metabolic syndrome, which showed higher levels of AT1 autoantibodies than non-parkinsonian controls. This is consistent with our recent studies, showing significant increase of AT1 and ACE2 autoantibodies in parkinsonian patients, which was related to dopaminergic degeneration and neuroinflammation. Altogether may lead to a vicious circle enhancing the progression of the disease that may be inhibited by strategies against production of these autoantibodies or AT1 receptor blockers (ARBs)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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11. A Phase 1-2 Study of Rovalpituzumab Tesirine in Combination With Nivolumab Plus or Minus Ipilimumab in Patients With Previously Treated Extensive-Stage SCLC.
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Malhotra J, Nikolinakos P, Leal T, Lehman J, Morgensztern D, Patel JD, Wrangle JM, Curigliano G, Greillier L, Johnson ML, Ready N, Robinet G, Lally S, Maag D, Valenzuela R, Blot V, and Besse B
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- Antibodies, Monoclonal, Humanized, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Benzodiazepinones, Humans, Ipilimumab therapeutic use, Nivolumab therapeutic use, Immunoconjugates therapeutic use, Lung Neoplasms drug therapy
- Abstract
Introduction: This open-label, phase 1-2 study evaluated the safety and efficacy of rovalpituzumab tesirine (Rova-T), an antibody-drug conjugate targeting DLL3, plus immune checkpoint inhibitors nivolumab plus or minus ipilimumab in previously treated extensive-stage SCLC (ES SCLC)., Methods: Patients with histologically or cytologically confirmed, previously treated (two or more lines of therapy) ES SCLC were enrolled into two cohorts. Cohort 1 received 0.3 mg/kg Rova-T (once every 6 wk for two cycles) plus 360 mg nivolumab (two 3-wk cycles beginning on week 4). Cohort 2 received the same dosage of Rova-T as cohort 1 plus 1 mg/kg nivolumab (four 3-wk cycles) and 1 mg/kg ipilimumab (beginning week 4). Both cohorts received 480 mg nivolumab every 4 weeks starting at week 10. Key objectives were to evaluate safety and tolerability and efficacy (per Response Evaluation Criteria in Solid Tumors version 1.1). The response-related results are based on centrally read data., Results: A total of 42 patients received therapy: cohort 1, n = 30; cohort 2, n = 12. Overall, 43% received two or more previous lines of therapy. All patients experienced one or more treatment-emergent adverse event (TEAE); 41 patients reported AEs considered related to the study drug by the investigator. The most frequent TEAE was pleural effusion (n = 20, 48%); most common grade greater than or equal to 3 was anemia (n = 9, 21%). Three grade 5 TEAEs considered related to the study drug were reported (cohort 1): pneumonitis (n = 2), acute kidney injury (n = 1). The objective response rate was 30% (12 of 40): cohort 1, 27.6% (8 of 29); cohort 2, 36.4% (4 of 11); all partial responses., Conclusions: Despite encouraging antitumor activity in previously treated ES SCLC, combination therapy with Rova-T and nivolumab plus or minus ipilimumab was not well tolerated at the dose levels and administration schedules evaluated., (Copyright © 2021 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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12. Reducing anticholinergic medication exposure among older adults using consumer technology: Protocol for a randomized clinical trial.
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Abebe E, Campbell NL, Clark DO, Tu W, Hill JR, Harrington AB, O'Neal G, Trowbridge KS, Vallejo C, Yang Z, Bo N, Knight A, Alamer KA, Carter A, Valenzuela R, Adeoye P, Boustani MA, and Holden RJ
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- Aged, Drug Prescriptions, Humans, Independent Living, Primary Health Care, Randomized Controlled Trials as Topic, Cholinergic Antagonists adverse effects, Quality of Life
- Abstract
Introduction: A growing body of scientific evidence points to the potentially harmful cognitive effects of anticholinergic medications among older adults. Most interventions designed to promote deprescribing of anticholinergics have directly targeted healthcare professionals and have had mixed results. Consumer-facing technologies may provide a unique benefit by empowering patients and can complement existing healthcare professional-centric efforts., Methods: We initiated a randomized clinical trial to evaluate the effectiveness of a patient-facing mobile application (Brain Safe app) compared to an attention control medication list app in reducing anticholinergic exposure among community-dwelling older adults. Study participants are adults aged 60 years and above, currently using at least one prescribed strong anticholinergic, and receiving primary care. The trial plans to enroll a total of 700 participants, randomly allocated in 1:1 proportion to the two study arms. Participants will have the Brain Safe app (intervention arm) or attention control medication list app (control arm) loaded onto a smartphone (study provided or personal device). All participants will be followed for 12 months and will have data collected at baseline, at 6 months, and 12 months by blinded outcome assessors. The primary outcome of the study is anticholinergic exposure measured as total standard daily dose (TSDD) computed from medication prescription electronic records. Secondary outcomes of the study are cognitive function and health-related quality of life., Discussion: A consumer-facing intervention to promote deprescribing of potentially high-risk medications can be part of a multi-pronged approach to reduce inappropriate medication use among older adult patients. Delivering a deprescribing intervention via a mobile app is a novel approach and may hold great promise to accelerate deployment of medication safety initiatives across diverse patient populations., Clinical Trial Registration: Registered at ClinicalTrials.gov on October 10, 2019. Identifier number: NCT04121858., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2021
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13. Suppression of high-fat diet-induced obesity-associated liver mitochondrial dysfunction by docosahexaenoic acid and hydroxytyrosol co-administration.
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Ortiz M, Soto-Alarcón SA, Orellana P, Espinosa A, Campos C, López-Arana S, Rincón MA, Illesca P, Valenzuela R, and Videla LA
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- Animals, Diet, High-Fat adverse effects, Docosahexaenoic Acids administration & dosage, Humans, Insulin Resistance, Lipid Metabolism drug effects, Male, Mice, Mice, Inbred C57BL, Phenylethyl Alcohol administration & dosage, Phenylethyl Alcohol pharmacology, Random Allocation, Docosahexaenoic Acids pharmacology, Liver metabolism, Non-alcoholic Fatty Liver Disease prevention & control, Obesity prevention & control, Phenylethyl Alcohol analogs & derivatives
- Abstract
Objective: Obesity-induced by high-fat diet (HFD) is associated with liver steatosis, oxidative stress and mitochondrial dysfunction, which can be eluded by the co-administration of the lipid metabolism modulator docosahexaenoic acid (DHA) and the antioxidant hydroxytyrosol (HT)., Methods: C57BL/6J mice fed a HFD were orally administered either with vehicle, DHA, HT or DHA+HT for 12 weeks. We measured parameters related to insulin resistance, serum lipid levels, liver fatty acid (FA) content and steatosis score, concomitantly with those associated with mitochondrial energy functions modulated by the transcriptional coactivator PGC-1a., Results: HFD induced insulin resistance, liver steatosis with n-3 FA depletion, and loss of mitochondrial respiratory functions with diminished NAD
+ /NADH ratio and ATP levels compared with CD, with the parallel decrease in the expression of the components of the PGC-1α cascade, namely, PPAR-α, FGF21 and AMPK, effects that were not observed in mice subjected to DHA and HT co-administration., Conclusions: Data presented indicate that the combination of DHA and HT prevents the development of liver steatosis and the associated mitochondrial dysfunction induced by HFD, thus strengthening the significance of this protocol as a therapeutic strategy avoiding disease evolution into more irreversible forms characterised by the absence of adequate pharmacological therapy in human obesity., (Copyright © 2020. Published by Elsevier Ltd.)- Published
- 2020
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14. Angiotensin type 2 receptors: Role in aging and neuroinflammation in the substantia nigra.
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Rodriguez-Perez AI, Garrido-Gil P, Pedrosa MA, Garcia-Garrote M, Valenzuela R, Navarro G, Franco R, and Labandeira-Garcia JL
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- Animals, Mice, Receptor, Angiotensin, Type 1 genetics, Receptor, Angiotensin, Type 1 metabolism, Substantia Nigra metabolism, Aging, Oxidative Stress, Receptor, Angiotensin, Type 2 genetics, Receptor, Angiotensin, Type 2 metabolism
- Abstract
Overactivity of the angiotensin-type-1 receptor (AT1)/NADPH-oxidase axis enhances aging processes, neuroinflammation and neurodegeneration. The role of AT2 receptors in the above-mentioned AT1-related effects in the aged brain, particularly substantia nigra, was investigated in this study. In the nigra, we observed a progressive decrease in AT2 mRNA expression with aging, and AT2 deletion led to changes in spontaneous motor behavior, dopamine receptors, renin-angiotensin system, and pro-oxidative and pro-inflammatory markers similar to those observed in aged wild type (WT) mice. Both aged WT mice and young AT2 KO mice showed an increased AT1, decreased MAS receptor and increased angiotensinogen mRNA and/or protein expression, as well as upregulation of pro-oxidative and pro-inflammatory markers. In cultures of microglial cells, activation of AT2 receptors inhibited the LPS-induced increase in AT1 mRNA and protein expression and neuroinflammatory markers. Both in AT2 KO microglial cultures and microglia obtained from adult AT2 KO mice, an increase in AT1 mRNA expression was observed. In cultured dopaminergic neurons, AT2 activation down-regulated AT1 mRNA and protein, and dopaminergic neurons from adult AT2 KO mice showed upregulation of AT1 mRNA expression. Both in microglia and dopaminergic neurons the pathway AT2/nitric oxide/cyclic guanosine monophosphate mediates the regulation of the AT1 mRNA and protein expression through downregulation of the Sp1 transcription factor. MAS receptors are also involved in the regulation of AT1 mRNA and protein expression by AT2. The results suggest that an aging-related decrease in AT2 expression plays a major role in the aging-related AT1 overexpression and AT1-related pro-inflammatory pro-oxidative effects., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
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15. Desmoid fibromatosis following surgical resection of spinal meningioma.
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Mujtaba B, Call C, Rowland F, Spear RP, Amini B, Valenzuela R, and Nassar S
- Abstract
A 42-year-old female patient with a history of cervicothoracic junction meningioma World Health Organization grade I, resected in early 2011, was admitted to the hospital with intractable headache and lower extremity weakness. Magnetic resonance imaging (MRI) showed an epidural mass compressing the spinal cord at the prior surgical site, which was interpreted as recurrent meningioma. Following surgical resection, histopathological analysis revealed desmoid fibromatosis (desmoid tumor). In retrospect, dynamic contrast-enhanced magnetic resonance imaging performed prior to surgery should have allowed for prospective exclusion of meningioma as the recurrent mass and suggested an alternative diagnosis such as post-traumatic desmoid fibromatosis or the need for biopsy to confirm diagnosis., (© 2020 Published by Elsevier Inc. on behalf of University of Washington.)
- Published
- 2020
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16. Needs assessment for a formal emergency medicine residency program in southern Madagascar.
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Mockler G, Rakotoarivelo RA, Ranaivo J, Valenzuela R, Pierson K, Calix D, and Mallon W
- Abstract
Introduction: World Health Organization data for Madagascar reveal that the nation's under age five mortality rate is 56/1000, and that its maternal mortality rate is 440/100,000. Malaria, leprosy, plague, and tuberculosis remain significant communicable disease threats. Malnutrition rates are improving but continue to impact negatively on the general health of the Malagasy population, especially in the southern region with its 1.9 million inhabitants. There are no emergency medicine (EM) training programs to serve the southern half of Madagascar, which has a large urban population in Fianarantsoa. This study aimed to assess the need for and potential feasibility of an emergency medicine training program in southern Madagascar., Methods: We met with the institutional leadership on site at the university hospital in Fianarantsoa. A needs assessment was performed on multiple domains. Domain 1: existing hospital infrastructure and its physical plant and emergency centre (EC) space allotment. Domain 2: existing clinical and technological resources. Domain 3: educational resources and the existing curriculum for EM. Domain 4: medical student educational program and availability of prospective residency candidates. Domain 5: pre-hospital care and emergency medical services., Results: The size of the EC is adequate for the current census. Clinical resources are typical of many developing countries, with significant need for technological advancement and support, which we delineate in the body of our paper. There is an existing curriculum in Antananarivo and in Majanga, as well as one available through the African Federation for Emergency Medicine. The medical school in the area is relatively new, with graduating classes numbering approximately 30. There is no organised pre-hospital care system, no 9-1-1 equivalent, and no pre-hospital treatment from within metropolitan Fianarantsoa., Conclusions: While the needs assessment indicates substantial need for emergency medicine development in southern Madagascar, the yield (particularly for the metropolitan Fianarantsoa area) would serve the population well., Competing Interests: The authors have no conflicts of interest to declare.
- Published
- 2019
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17. Crosstalk mechanisms in hepatoprotection: Thyroid hormone-docosahexaenoic acid (DHA) and DHA-extra virgin olive oil combined protocols.
- Author
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Valenzuela R and Videla LA
- Subjects
- Animals, Diet, High-Fat, Drug Therapy, Combination, Humans, Liver metabolism, Non-alcoholic Fatty Liver Disease metabolism, Reperfusion Injury metabolism, Docosahexaenoic Acids therapeutic use, Liver drug effects, Non-alcoholic Fatty Liver Disease drug therapy, Olive Oil therapeutic use, Reperfusion Injury drug therapy, Triiodothyronine therapeutic use
- Abstract
Normal liver function includes a number of metabolic processes, secretion of cellular mediators and its role in immunobiology; these require a high energy supply, which is further enhanced under adverse conditions triggering hepatic disorders or injury due to the operation of counteracting mechanisms. Alterations in oxygen availability, such as ischemia-reperfusion (IR) leading to liver inflammation and high-fat diet (HFD)-induced hepatic steatosis, are noxious responses encountered in hepatic surgery and obesity, respectively. Several strategies have been developed to attenuate or prevent these disorders, including thyroid hormone (T
3 ), docosahexaenoic acid (DHA) and extra virgin olive oil (EVOO). These hormetic agents that exert beneficial effects in the low dose range were shown to abrogate IR-induced liver injury effectively in the case of T3 , DHA, or their combined administration, whereas DHA plus EVOO attenuate HFD-induced hepatic steatosis, although they can induce adverse effects in other experimental settings. The use of combined hepatoprotective protocols (DHA + T3 or DHA + EVOO) using low doses or reduced supplementation periods is characterized by the stimulation of different types of molecular defensive mechanisms and similar signaling processes that exhibit synergism, thus constituting suitable experimental liver pharmacological preconditioning strategies with possible future clinical applications., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
18. Efficacy and safety of withholding antimicrobial treatment in children with cancer, fever and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial.
- Author
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Santolaya ME, Alvarez AM, Acuña M, Avilés CL, Salgado C, Tordecilla J, Varas M, Venegas M, Villarroel M, Zubieta M, Toso A, Bataszew A, Farfán MJ, de la Maza V, Vergara A, Valenzuela R, and Torres JP
- Subjects
- Adolescent, Child, Child, Preschool, Chile, Hospitals, Humans, Infant, Infant, Newborn, Male, Neoplasms complications, Prospective Studies, Treatment Outcome, Anti-Infective Agents administration & dosage, Febrile Neutropenia drug therapy, Respiratory Tract Infections drug therapy, Virus Diseases drug therapy, Withholding Treatment
- Abstract
Objectives: To determine efficacy and safety of withholding antimicrobials in children with cancer, fever and neutropenia (FN) with a demonstrated respiratory viral infection., Methods: Prospective, multicentre, randomized study in children presenting with FN at five hospitals in Santiago, Chile, evaluated at admission for diagnosis of bacterial and viral pathogens including PCR-microarray for 17 respiratory viruses. Children positive for a respiratory virus, negative for a bacterial pathogen and with a favourable evolution after 48 h of antimicrobial therapy were randomized to either maintain or withhold antimicrobials. Primary endpoint was percentage of episodes with uneventful resolution. Secondary endpoints were days of fever/hospitalization, bacterial infection, sepsis, admission to paediatric intensive care unit (PICU) and death., Results: A total of 319 of 951 children with FN episodes recruited between July 2012 and December 2015 had a respiratory virus as a unique identified microorganism, of which 176 were randomized, 92 to maintain antimicrobials and 84 to withdraw. Median duration of antimicrobial use was 7 days (range 7-9 days) versus 3 days (range 3-4 days), with similar frequency of uneventful resolution (89/92 (97%) and 80/84 (95%), respectively, not significant; OR 1.48; 95% CI 0.32-6.83, p 0.61), and similar number of days of fever (2 versus 1), days of hospitalization (6 versus 6) and bacterial infections throughout the episode (2%-1%), with one case of sepsis requiring admission to PICU in the group that maintained antimicrobials, without any deaths., Conclusions: The reduction of antimicrobials in children with FN and respiratory viral infections, based on clinical and microbiological/molecular diagnostic criteria, should favour the adoption of evidence-based management strategies in this population., (Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
19. Critical period for dopaminergic neuroprotection by hormonal replacement in menopausal rats.
- Author
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Rodriguez-Perez AI, Borrajo A, Valenzuela R, Lanciego JL, and Labandeira-Garcia JL
- Subjects
- Angiotensin Receptor Antagonists administration & dosage, Angiotensin Receptor Antagonists pharmacology, Animals, Cells, Cultured, Female, Nerve Degeneration chemically induced, Nerve Degeneration pathology, Nerve Degeneration prevention & control, Oxidopamine, Rats, Sprague-Dawley, Time Factors, Dopaminergic Neurons drug effects, Dopaminergic Neurons pathology, Estrogen Receptor alpha physiology, Estrogen Replacement Therapy, Estrogens administration & dosage, Estrogens pharmacology, Menopause, Neuroprotective Agents, Parkinson Disease drug therapy, Parkinson Disease pathology, Renin-Angiotensin System physiology
- Abstract
The neuroprotective effects of menopausal hormonal therapy in Parkinson's disease have not yet been clarified, and it is not known whether there is a critical period. Estrogen induced significant protection against 6-hydroxydopamine-induced dopaminergic degeneration when administered immediately or 6 weeks, but not 20 weeks after ovariectomy. In the substantia nigra, ovariectomy induced a decrease in levels of estrogen receptor-α and increased angiotensin activity, NADPH-oxidase activity, and expression of neuroinflammatory markers, which were regulated by estrogen administered immediately or 6 weeks but not 20 weeks after ovariectomy. Interestingly, treatment with angiotensin receptor antagonists after the critical period induced a significant level of neuroprotection. In cultures, treatment with 1-methyl-4-phenylpyridinium induced an increase in astrocyte-derived angiotensinogen and dopaminergic neuron death, which were inhibited by estrogen receptor α agonists. In microglial cells, estrogen receptor β agonists inhibited the angiotensin-induced increase in inflammatory markers. The results suggest that there is a critical period for the neuroprotective effect of estrogen against dopaminergic cell death, and local estrogen receptor α and renin-angiotensin system play a major role., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
20. Aging-related dysregulation of dopamine and angiotensin receptor interaction.
- Author
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Villar-Cheda B, Dominguez-Meijide A, Valenzuela R, Granado N, Moratalla R, and Labandeira-Garcia JL
- Subjects
- Aging metabolism, Animals, Corpus Striatum metabolism, Corpus Striatum pathology, Dopamine genetics, Dopamine metabolism, Dopaminergic Neurons physiology, Down-Regulation, Gene Expression, Inflammation genetics, Male, Mice, Oxidative Stress genetics, Parkinson Disease genetics, Parkinson Disease pathology, Rats, Rats, Sprague-Dawley, Receptor, Angiotensin, Type 1 genetics, Receptor, Angiotensin, Type 1 metabolism, Receptors, Dopamine genetics, Receptors, Dopamine metabolism, Renin-Angiotensin System physiology, Risk, Substantia Nigra metabolism, Substantia Nigra pathology, Aging genetics, Dopamine physiology, Receptor, Angiotensin, Type 1 physiology
- Abstract
It is not known whether the aging-related decrease in dopaminergic function leads to the aging-related higher vulnerability of dopaminergic neurons and risk for Parkinson's disease. The renin-angiotensin system (RAS) plays a major role in the inflammatory response, neuronal oxidative stress, and dopaminergic vulnerability via type 1 (AT1) receptors. In the present study, we observed a counterregulatory interaction between dopamine and angiotensin receptors. We observed overexpression of AT1 receptors in the striatum and substantia nigra of young adult dopamine D1 and D2 receptor-deficient mice and young dopamine-depleted rats, together with compensatory overexpression of AT2 receptors or compensatory downregulation of angiotensinogen and/or angiotensin. In aged rats, we observed downregulation of dopamine and dopamine receptors and overexpression of AT1 receptors in aged rats, without compensatory changes observed in young animals. L-Dopa therapy inhibited RAS overactivity in young dopamine-depleted rats, but was ineffective in aged rats. The results suggest that dopamine may play an important role in modulating oxidative stress and inflammation in the substantia nigra and striatum via the RAS, which is impaired by aging., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
21. Aging-related changes in the nigral angiotensin system enhances proinflammatory and pro-oxidative markers and 6-OHDA-induced dopaminergic degeneration.
- Author
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Villar-Cheda B, Valenzuela R, Rodriguez-Perez AI, Guerra MJ, and Labandeira-Garcia JL
- Subjects
- Aging metabolism, Angiotensin II Type 1 Receptor Blockers pharmacology, Animals, Benzimidazoles pharmacology, Biphenyl Compounds, Dopaminergic Neurons metabolism, Male, Molecular Targeted Therapy, Nerve Degeneration, Parkinson Disease etiology, Parkinson Disease therapy, Rats, Rats, Sprague-Dawley, Receptor, Angiotensin, Type 1 physiology, Substantia Nigra pathology, Tetrazoles pharmacology, Aging pathology, Aging physiology, Angiotensin II physiology, Dopaminergic Neurons pathology, Inflammation Mediators metabolism, Interleukin-1beta metabolism, NADPH Oxidases metabolism, Oxidative Stress, Oxidopamine pharmacology, Reactive Oxygen Species metabolism, Substantia Nigra metabolism, Tumor Necrosis Factor-alpha metabolism
- Abstract
An age-related proinflammatory, pro-oxidant state in the nigra may increase the vulnerability of dopaminergic neurons to additional damage. Angiotensin II, via type 1 (AT1) receptors, is one of the most important known inflammation and oxidative stress inducers. However, it is not known if there are age-related changes in the nigral angiotensin system. In aged rats, we observed increased activation of the nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) complex and increased levels of the proinflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α, which indicate pro-oxidative, proinflammatory state in the nigra. We also observed enhanced 6-hydroxydopamine (6-OHDA)-induced dopaminergic cell death in aged rats. This is associated with increased expression of AT1 receptors and decreased expression of AT2 receptors in aged rats, and is reduced by treatment with the AT1 antagonist candesartan. The present results indicate that brain angiotensin is involved in changes that may increase the risk of Parkinson's disease with aging. Furthermore, the results suggest that manipulation of the brain angiotensin system may constitute an effective neuroprotective strategy against aging-related risk of dopaminergic degeneration., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
22. Apolipoprotein E receptor 2 is involved in the thrombotic complications in a murine model of the antiphospholipid syndrome.
- Author
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Romay-Penabad Z, Aguilar-Valenzuela R, Urbanus RT, Derksen RH, Pennings MT, Papalardo E, Shilagard T, Vargas G, Hwang Y, de Groot PG, and Pierangeli SS
- Subjects
- Animals, Antibodies, Antiphospholipid adverse effects, Antibodies, Antiphospholipid metabolism, Antibodies, Antiphospholipid pharmacology, Antibodies, Monoclonal administration & dosage, Antibodies, Monoclonal pharmacology, Antibodies, Phospho-Specific administration & dosage, Antibodies, Phospho-Specific adverse effects, Antibodies, Phospho-Specific pharmacology, Antiphospholipid Syndrome complications, Antiphospholipid Syndrome pathology, Antiphospholipid Syndrome prevention & control, Disease Models, Animal, Drug Evaluation, Preclinical, Humans, Immunoglobulin G administration & dosage, Immunoglobulin G adverse effects, Immunoglobulin G pharmacology, LDL-Receptor Related Proteins genetics, LDL-Receptor Related Proteins metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Middle Aged, Thrombosis etiology, Thrombosis pathology, beta 2-Glycoprotein I immunology, Antiphospholipid Syndrome genetics, LDL-Receptor Related Proteins physiology, Thrombosis genetics
- Abstract
Antiphospholipid (aPL)/anti-β(2) glycoprotein I (anti-β(2)GPI) antibodies stimulates tissue factor (TF) expression within vasculature and in blood cells, thereby leading to increased thrombosis. Several cellular receptors have been proposed to mediate these effects, but no convincing evidence for the involvement of a specific one has been provided. We investigated the role of Apolipoprotein E receptor 2 (ApoER2') on the pathogenic effects of a patient-derived polyclonal aPL IgG preparation (IgG-APS), a murine anti-β(2)GPI monoclonal antibody (E7) and of a constructed dimeric β(2)GPI I (dimer), which in vitro mimics β(2)GPI-antibody immune complexes, using an animal model of thrombosis, and ApoER2-deficient (-/-) mice. In wild type mice, IgG-APS, E7 and the dimer increased thrombus formation, carotid artery TF activity as well as peritoneal macrophage TF activity/expression. Those pathogenic effects were significantly reduced in ApoER2 (-/-) mice. In addition, those effects induced by the IgG-APS, by E7 and by the dimer were inhibited by treatment of wild-type mice with soluble binding domain 1 of ApoER2 (sBD1). Altogether these data show that ApoER2 is involved in pathogenesis of antiphospholipids antibodies.
- Published
- 2011
- Full Text
- View/download PDF
23. First experience in human beings with a permanently implantable intrasac pressure transducer for monitoring endovascular repair of abdominal aortic aneurysms.
- Author
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Ellozy SH, Carroccio A, Lookstein RA, Minor ME, Sheahan CM, Juta J, Cha A, Valenzuela R, Addis MD, Jacobs TS, Teodorescu VJ, and Marin ML
- Subjects
- Angioplasty, Aorta, Abdominal diagnostic imaging, Aortic Aneurysm, Abdominal surgery, Blood Pressure, Electrodes, Implanted, Equipment Design, Follow-Up Studies, Humans, Stents, Ultrasonography, Aorta, Abdominal physiopathology, Aortic Aneurysm, Abdominal physiopathology, Blood Pressure Monitoring, Ambulatory instrumentation, Transducers, Pressure
- Abstract
Objectives: Endovascular stent graft repair of abdominal aortic aneurysms (AAAs) prevents rupture by excluding the aneurysm sac from systemic arterial pressure. Current surveillance protocols after endovascular aneurysm repair (EVAR) follow secondary markers of sac pressurization, namely, endoleak and sac enlargement. We report the first clinical experience with the use of a permanently implantable, ultrasound-activated remote pressure transducer to measure intrasac pressure after EVAR., Methods: Over 7 months, 14 patients underwent EVAR of an infrarenal abdominal aortic aneurysm with implantation of an ultrasound-activated remote pressure transducer fixed to the outside of the stent graft and exposed to the excluded aortic sac. Twelve patients received modular bifurcated stent grafts, and 2 patients received aortouniiliac devices. Intrasac pressures were measured directly with an intravascular catheter and by the remote sensor at stent-graft deployment. Follow-up sac pressures were measured with a remote sensor and correlated with systemic arterial pressure at every follow-up visit. Mean follow-up was 2.6 +/-1.9 months., Results: Excellent concordance was found between catheter-derived and transducer-derived intrasac pressssure intraoperatively. Pulsatile waveforms were seen in all functioning transducers at each evaluation interval. One implant ceased to function at 2 months of follow-up. In 1 patient a type I endoleak was diagnosed on 1-month computed tomography (CT) scans; 3 type II endoleaks were observed. Those patients with complete exclusion of the aneurysm on CT scans had a significant difference in systemic and sac systolic pressures initially (P <.001) and at 1 month (P <.001). Initial sac diastolic pressures were higher than systemic diastolic pressures (P <.001). The ratio of systemic to sac systolic pressure increased over time in those patients with complete aneurysm exclusion ( P <.001). Four of 6 patients with no endoleak and greater than 1-month follow-up had diminution of sac systolic pressure to 40 mm Hg or less by 3 months., Conclusion: This is the first report of a totally implantable chronic pressure transducer to monitor the results of EVAR in human beings. Aneurysm exclusion leads to gradual diminution of sac pressure over several months. Additional clinical follow-up will be necessary to determine whether aneurysm sac pressure monitoring can replace CT in the long-term surveillance of patients after EVAR.
- Published
- 2004
- Full Text
- View/download PDF
24. The role of aortic stent grafting in the treatment of atheromatous embolization syndrome: results after a mean of 15 months follow-up.
- Author
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Carroccio A, Olin JW, Ellozy SH, Lookstein RA, Valenzuela R, Minor ME, Sheahan CM, Teodorescu VJ, and Marin ML
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal complications, Aortic Aneurysm, Abdominal diagnostic imaging, Embolism, Cholesterol complications, Embolism, Cholesterol diagnostic imaging, Female, Follow-Up Studies, Humans, Male, Radiography, Retrospective Studies, Syndrome, Treatment Outcome, Angioplasty, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation, Embolism, Cholesterol surgery, Stents
- Abstract
Background: Endovascular stent-graft (ESG) repair of abdominal aortic aneurysm (AAA) has emerged as an alternative to open surgery. The role of ESG in patients with challenging medical and anatomic problems remains an area of general debate. This study reviews an experience with stent grafts to treat patients with AAA and atheromatous embolization syndrome (AES) presenting with chronic distal embolization (CDE)., Methods: Over a 5-year period 660 patients with AAA were treated with aortic stent grafts. Patients with AAA and ischemic ulcerations or toe gangrene due to CDE despite palpable foot pulses were investigated for successful aneurysm exclusion, resolution of ischemic symptoms, complications and survival. Follow-up averaged 15.3 +/- 14.9 months (range, 1 to 60 months)., Results: Nineteen patients had AAA and manifestations of CDE. The population (16 males/3 females) had a mean age of 79 +/- 7 years and mean aneurysm diameter of 5.5 cm. Renal insufficiency was present in 5/19 (26 %). Ischemia presented as ischemic ulcers (16/19 [84.2%]) or toe gangrene (3/19 [15.8%]). Stent grafts included 6 aortouniiliac and 13 bifurcated devices. Exclusion was achieved in all but 2 patients who had type II lumbar endoleaks. At 30-day postoperative follow-up, mortality was 0 % and resolution of CDE/ischemia was noted in 2 of 19 (10.5%) patients. Eight of 9 patients with follow-up of 1 year had complete resolution of their ischemic symptoms, with no recurrent manifestations of AES. Complications included progression of renal insufficiency over an 18-month period in 1 patient and an unstable expanding pararenal aortic neck in 1 patient. Foot ischemia persisted at 1 year in a patient with severe coexisting thoracic aortic disease despite successful AAA exclusion. Six (31.6%) patients died during a mean follow-up of 15.3 months from causes unrelated to their AAA., Conclusion: On the basis of this experience, stent-graft repair of AAA and CDE may be an effective strategy to prevent future embolization. Recognition of coexisting thoracic aortic disease is essential. ESG does not address the extremely high morbidity and mortality from cardiovascular causes in this population.
- Published
- 2004
- Full Text
- View/download PDF
25. Imaging and clinical spectrum of rhabdomyosarcoma in children.
- Author
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Kim EE, Valenzuela RF, Kumar AJ, Raney RB, and Eftekari F
- Subjects
- Child, Female, Head and Neck Neoplasms diagnosis, Head and Neck Neoplasms pathology, Humans, Male, Neoplasm Staging, Retrospective Studies, Rhabdomyosarcoma diagnosis, Rhabdomyosarcoma secondary, Soft Tissue Neoplasms diagnosis, Magnetic Resonance Imaging, Rhabdomyosarcoma pathology, Soft Tissue Neoplasms pathology
- Abstract
We retrospectively analyzed the MRI findings of rhabdomyosarcoma (RMSA) in 23 patients to evaluate its role in staging and management. Heterogeneous signal abnormalities were noted in the sarcoma lesions with significant contrast enhancement. Seven head and neck cases showed direct bone invasion and destruction; only one had distant bony metastasis. Metastasis was noted in the lymph nodes, lung, bone, abdominoperitoneum, and head and neck soft tissue. MRI findings of RMSA are most helpful in staging and assessing therapeutic response.
- Published
- 2000
- Full Text
- View/download PDF
26. A revisit of MRI analysis for synovial sarcoma.
- Author
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Valenzuela RF, Kim EE, Seo JG, Patel S, and Yasko AW
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Female, Humans, Male, Middle Aged, Retrospective Studies, Magnetic Resonance Imaging, Sarcoma, Synovial pathology
- Abstract
We evaluated magnetic resonance imaging (MRI) findings of synovial sarcomas in 22 patients, and the most common MRI findings were oval and well-defined nodular masses with heterogeneous intermediate signal intensity (SI) on T1 weighted images (WI), high SI on T2-WI and heterogeneous contrast enhancement. A cystic component was seen in 77%, intratumoral hemorrhage in 73%, and calcification in three monophasic sarcomas. Metastases were noted in lung (mostly biphasic type), lymph node, and bone. Posttreatment changes revealed diffusely increased S1 on T2-W1 and slightly diffuse contrast enhancement with feathery appearance. Morphology and MR signal characteristics assist in synovial sarcoma management.
- Published
- 2000
- Full Text
- View/download PDF
27. Migraine, but not subarachnoid hemorrhage, is associated with differentially increased NPY-like immunoreactivity in the CSF.
- Author
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Valenzuela RF, Donoso MV, Mellado PA, and Huidobro-Toro JP
- Subjects
- Adult, Biomarkers, Chromogranin A, Chromogranins cerebrospinal fluid, Female, Humans, Male, Middle Aged, Migraine Disorders physiopathology, Neurons metabolism, Nitric Oxide physiology, Nitrites cerebrospinal fluid, Prospective Studies, Subarachnoid Hemorrhage physiopathology, Sympathetic Nervous System physiopathology, Cerebrospinal Fluid Proteins analysis, Migraine Disorders cerebrospinal fluid, Nerve Tissue Proteins cerebrospinal fluid, Neuropeptide Y cerebrospinal fluid, Subarachnoid Hemorrhage cerebrospinal fluid, Vasomotor System physiopathology
- Abstract
To test whether migraine and subarachnoid hemorrhage (SAH) are associated with increased sympathetic tone, we compared the neuropeptide Y-like (NPY-LI) and chromogranin A-like immunoreactivities (LI) of cerebrospinal fluid (CSF) from migraneurs and SAH patients with those from control subjects. Increased sympathetic tone was expected to produce higher co-release of these co-stored peptides and concordant changes in their CSF levels. In addition, we investigated a possible disturbed nitric oxide homeostasis by measuring CSF nitrites (NO). More than 70% of CSF NPY-LI corresponded to the chromatographic peak (HPLC) for the intact molecule in all three groups. Migraneurs had 64% higher CSF NPY-LI, but no significant difference in CSF chromogranin A-LI, as compared to controls. In contrast, SAH patients had 74% less CSF chromogranin A-LI and a trend to lower NPY-LI, as compared to controls. No differences in CSF NO were detected among groups. These results argue against an increased sympathetic tone in patients with either migraine or SAH, and suggest that the higher CSF NPY-LI of migraneurs probably originates from central neurons. Furthermore, our findings in SAH patients argue in favor of a decreased sympathetic tone; this could be a homeostatic response to counterbalance vasoconstriction mediated by other mechanisms.
- Published
- 2000
- Full Text
- View/download PDF
28. Cost containment in anesthesiology: a survey of department activities.
- Author
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Valenzuela RC and Johnstone RE
- Subjects
- Academic Medical Centers economics, Anesthesia Department, Hospital organization & administration, Drug Costs, Surveys and Questionnaires, Anesthesia Department, Hospital economics, Cost Control
- Abstract
Study Objective: To survey cost containment activities in anesthesiology and to determine to what extent departments use cost policies and guidelines., Design: Mail survey., Setting: Academic and large nonacademic anesthesiology departments., Measurements and Main Results: 147 responding departments answered 20 questions. 38% of surveys were returned. 90 responders identified themselves as academic departments and 57 responders as nonacademic. 73% of departments reported pressure from hospital administrators to reduce anesthesia costs. The most common cost-saving activity, used by 90% of departments, is improving operating room (OR) utilization. 53% of all departments have policies or guidelines to contain drug costs, while 48% of departments have these to contain other product costs. Departments reporting themselves as academic generally reported greater use of cost policies., Conclusions: Anesthesiology departments are experiencing pressure to reduce costs and the majority have cost policies and guidelines concerning utilization of ORs and anesthetic drugs. Academic anesthesiology departments may be experiencing more cost-containment pressure than nonacademic departments.
- Published
- 1997
- Full Text
- View/download PDF
29. Managing pharmaceutical sales activities in an academic anesthesiology department.
- Author
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Johnstone RE, Valenzuela RC, and Sullivan D
- Subjects
- Anesthesiology education, Cost Control, Costs and Cost Analysis, Academic Medical Centers economics, Anesthesiology economics, Anesthetics economics, Drug Industry economics, Marketing of Health Services economics
- Abstract
To contain costs, departments of anesthesiology must control the use of new, expensive drugs. Conflicts with pharmaceutical companies can arise when they promote drug sales. Pharmaceutical company sales represent anesthesiology department expenses. Anesthesiologists hold diverse opinions on this clash of interests, on the proper roles of pharmaceutical sales representatives in anesthesiology departments, and on the ethics of accepting industry gifts. Our department has managed pharmaceutical sales activities by encouraging discussion of the ethics and legal limits of industry gifts, by banning sales representatives from bringing food into the department, and by adopting The American Medical Association Guidelines on Gifts.
- Published
- 1995
- Full Text
- View/download PDF
30. Immunoelectrophoretic and immunohistochemical characterizations of fibrinogen derivatives in atherosclerotic aortic intimas and vascular prosthesis pseudo-intimas.
- Author
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Valenzuela R, Shainoff JR, DiBello PM, Urbanic DA, Anderson JM, Matsueda GR, and Kudryk BJ
- Subjects
- Antibodies, Monoclonal, Antigens, Cadaver, Fibrin Fibrinogen Degradation Products, Fibrinopeptide B analysis, Humans, Immunoelectrophoresis, Immunohistochemistry, Tissue Distribution, Aorta metabolism, Arteriosclerosis metabolism, Fibrinogen analogs & derivatives
- Abstract
Cadaveric aortic intimas with uncomplicated atherosclerosis were examined to determine the distribution and polypeptide chain composition of fibrinogen-related protein. Immunohistochemical staining showed deposits rich in fibrinopeptides A and B. The deposits were usually disseminated throughout intimas of moderate thickness < 0.7 mm, but were distributed focally in elongate patches bounded both lumenally and medially by deposit-free tissue in thick atheromas. Saline extracts generally showed undegraded monomers and dimers by electrophoresis. The residual protein contained A alpha and gamma-chains that were cross-linked predominantly (>80%) into unresolved high M(r) (>200 kd) derivatives, whereas B beta-chains were left non-cross-linked, as occurs in late stages of cross-linking by transglutaminases. The resolved components had electrophoretic mobilities corresponding to characteristic products of both factor XIIIa and tissue-transglutaminase. A greater incorporation of alpha- rather than gamma-chains into cross-linked products implicated tissue-transglutaminase as contributing heavily. By contrast, vascular graft pseudo-intimas and a cadaveric clot were rich in degraded fibrin devoid of fibrinopeptide A, and cross-linked in patterns typical of XIIIa with gamma 2 dimers constituting the principal product. The findings indicate that the fibrinogen in the aortic intima is comparatively well protected from thrombin and plasmin, and that much of it is deposited through direct cross-linking by tissue-transglutaminase without being converted to fibrin.
- Published
- 1992
31. Combined hamartomas of the retina and retinal pigment epithelium.
- Author
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Schachat AP, Shields JA, Fine SL, Sanborn GE, Weingeist TA, Valenzuela RE, and Brucker AJ
- Subjects
- Adolescent, Adult, Aged, Child, Child, Preschool, Diagnosis, Differential, Eye Neoplasms physiopathology, Female, Fluorescein Angiography, Follow-Up Studies, Hamartoma physiopathology, Humans, Infant, Male, Middle Aged, Ophthalmoscopy, Retinal Diseases physiopathology, Visual Acuity, Eye Neoplasms diagnosis, Hamartoma diagnosis, Pigment Epithelium of Eye, Retina
- Abstract
Combined hamartomas of the retina and retinal pigment epithelium are rare fundus lesions. By combining cases seen by members of The Macula Society, clinical data was collected on 60 patients with combined hamartomas. We reviewed the clinical presentations, ophthalmoscopic, and fluorescein angiographic features and differential diagnosis of this tumor. Of 41 patients with adequate follow-up information, 10 (24%) lost at least two lines of visual acuity, usually due to tractional distortion of the fovea, and four (10%) had improved visual acuity following either amblyopia therapy or vitreous surgery for macular traction.
- Published
- 1984
- Full Text
- View/download PDF
32. Artificial enrichment of white rice as a solution to endemic beriberi; report of field trials in Bataan, Philippines.
- Author
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SALCEDO J Jr, BAMBA MD, CARRASCO EO, CHAN GS, CONCEPCION I, JOSE FR, DE LEON JF, OLIVEROS SB, PASCUAL CR, SANTIAGO LC, and VALENZUELA RC
- Subjects
- Philippines, Beriberi, Oryza
- Published
- 1950
- Full Text
- View/download PDF
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