121 results on '"Avalos C"'
Search Results
2. Coupled charge and spin dynamics in high-density ensembles of nitrogen-vacancy centers in diamond
- Author
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Giri, R., Gorrini, F., Dorigoni, C., Avalos, C. E., Cazzanelli, M., Tambalo, S., and Bifone, A.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We studied the spin depolarization of ensembles of nitrogen-vacancy (NV) centers in nitrogen-rich single crystal diamonds. We found a strong dependence of the evolution of the polarized state in the dark on the concentration of NV centers. At low excitation power, we observed a simple exponential decay profile in the low-density regime and a paradoxical inverted exponential profile in the high-density regime. At higher excitation power, we observed complex behavior, with an initial sharp rise in luminescence signal after the preparation pulse followed by a slower exponential decay. Magnetic field and excitation laser power-dependent measurements suggest that the rapid initial increase of the luminescence signal is related to recharging of the nitrogen-vacancy centers (from neutral to negatively charged) in the dark. The slow relaxing component corresponds to the longitudinal spin relaxation of the NV ensemble. The shape of the decay profile reflects the interplay between two mechanisms: the NV charge state conversion in the dark and the longitudinal spin relaxation. These mechanisms, in turn, are influenced by ionization, recharging and polarization dynamics during excitation. Interestingly, we found that charge dynamics are dominant in NV-dense samples even at very feeble excitation power. These observations may be important for the use of ensembles of NV centers in precession magnetometry and sensing applications., Comment: 7 pages, 6 figures
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- 2017
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3. Selenoprotein deficiency disorder predisposes to aortic aneurysm formation.
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Schoenmakers, E., Marelli, F., Jørgensen, H.F., Visser, Wesley J., Moran, C., Groeneweg, S., Avalos, C., Jurgens, S.J., Figg, N., Finigan, A., Wali, N., Agostini, M., Wardle-Jones, H., Lyons, G., Rusk, R., Gopalan, D., Twiss, P., Visser, J.J.C.M., Goddard, M., Nashef, S.A.M., Heijmen, R.H., Clift, P., Sinha, S., Pirruccello, J.P., Ellinor, P.T., Busch-Nentwich, E.M., Ramirez-Solis, R., Murphy, M.P., Persani, L., Bennett, M., Chatterjee, K., Schoenmakers, E., Marelli, F., Jørgensen, H.F., Visser, Wesley J., Moran, C., Groeneweg, S., Avalos, C., Jurgens, S.J., Figg, N., Finigan, A., Wali, N., Agostini, M., Wardle-Jones, H., Lyons, G., Rusk, R., Gopalan, D., Twiss, P., Visser, J.J.C.M., Goddard, M., Nashef, S.A.M., Heijmen, R.H., Clift, P., Sinha, S., Pirruccello, J.P., Ellinor, P.T., Busch-Nentwich, E.M., Ramirez-Solis, R., Murphy, M.P., Persani, L., Bennett, M., and Chatterjee, K.
- Abstract
Contains fulltext : 300228.pdf (Publisher’s version ) (Open Access), Aortic aneurysms, which may dissect or rupture acutely and be lethal, can be a part of multisystem disorders that have a heritable basis. We report four patients with deficiency of selenocysteine-containing proteins due to selenocysteine Insertion Sequence Binding Protein 2 (SECISBP2) mutations who show early-onset, progressive, aneurysmal dilatation of the ascending aorta due to cystic medial necrosis. Zebrafish and male mice with global or vascular smooth muscle cell (VSMC)-targeted disruption of Secisbp2 respectively show similar aortopathy. Aortas from patients and animal models exhibit raised cellular reactive oxygen species, oxidative DNA damage and VSMC apoptosis. Antioxidant exposure or chelation of iron prevents oxidative damage in patient's cells and aortopathy in the zebrafish model. Our observations suggest a key role for oxidative stress and cell death, including via ferroptosis, in mediating aortic degeneration.
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- 2023
4. Spatial point process modeling applied to the assessment of risk factors associated with forest wildfires incidence in Castellón, Spain
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Aragó, P., Juan, P., Díaz-Avalos, C., and Salvador, P.
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- 2016
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5. Arsenic removal enhanced by the use of ultrafiltration
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de Carvalho, F, primary, Masetto, N, additional, Lima, A, additional, Arbelaez, J, additional, Ramos, R, additional, Avalos, C, additional, and Quiñones, O, additional
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- 2014
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6. Myliobatis freminvillii, bullnose eagle ray
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Carlson, J., Charvet, P., Avalos, C., Blanco Parra, M. P., Briones Bell lloch, A., Cardeñosa, D., Chiaramonte, Gustavo Enrique, Cuevas, J.M., Derrick, D., Espinoza, E., Mejía Falla, P. A., Morales Saldaña, J. M., Motta, F., Naranjo Elizondo, B., Pacoureau, N., Paesch, L., Perez Jiménez, J. C., Rincon, G., Schneider, E. V. C., Simpson, N. J., Talwar, B. S., and Pollom, R.
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purl.org/becyt/ford/1 [https] ,Myliobatiformes ,Myliobatidae ,Bullnose Eagle Ray ,purl.org/becyt/ford/1.6 [https] ,Chondrichthyes - Abstract
The Bullnose Eagle Ray (Myliobatis freminvillii) is a medium-sized (to 106 cm disc width) demersal coastal eagle ray that occurs in the Northwest, Western Central, and Southwest Atlantic Oceans from Massachussetts, USA to the Texas coast of the Gulf of Mexico and from Venezuela to Buenos Aires, Argentina and inhabits continental shelves from the surface to a depth of 122 m. Its is captured by artisanal longlines, gillnets, beach seines and also in industrial shrimp trawls. In the Northwest Atlantic, population trend data are available from a deep-water trawl survey in the northern Gulf of Mexico that reveal steep increases in abundance over 2002-2013. There are no known threats in the Northwest and Western Central Atlantic, but in the Southwest Atlantic artisanal fisheries are intense. Further, there are largely unmanaged commercial trawl and longline fisheries in this area. This inshore eagle ray is exposed to intense and often unmanaged fishing pressure throughout the Southwest Atlantic portion of its range, and it has no refuge at depth. Due to the level of exploitation by widespread artisanal fisheries which lack adequate management, it is suspected that this species has undergone a population reduction of >80% over the past three generation lengths (44 years) in the Atlantic South American part of its range, but is stable in the Northwest and Western Central Atlantic. Overall, based on its range, with almost all threats found in the Southwest Atlantic, and the suspected low productivity of the species, the Bullnose Eagle Ray is suspected to have undergone a population reduction of 30-49% in the past three generation lengths (44 years) due to levels of exploitation, and it is assessed as Vulnerable A2bd. Fil: Carlson, J.. National Marine Fisheries Service; Estados Unidos Fil: Charvet, P.. Universidade Federal do Paraná; Brasil Fil: Avalos, C.. Fundacion Mundo Azul; Guatemala Fil: Blanco Parra, M. P.. Universidad de Quintana Roo; México Fil: Briones Bell lloch, A.. Direccion de Regulaciones Pesqueras y Ciencias; Cuba Fil: Cardeñosa, D.. Florida International University; Estados Unidos Fil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); Argentina Fil: Cuevas, J.M.. Wildlife Conservation Society; Estados Unidos Fil: Derrick, D.. University Fraser Simon; Canadá Fil: Espinoza, E.. Direccion Parque Nacional Galapagos; Ecuador Fil: Mejía Falla, P. A.. Wildlife Conservation Society; Estados Unidos Fil: Morales Saldaña, J. M.. Smithsonian Tropical Research Institute; Panamá Fil: Motta, F.. Universidade Federal de Sao Paulo; Brasil Fil: Naranjo Elizondo, B.. Universidad de Costa Rica; Costa Rica Fil: Pacoureau, N.. University Fraser Simon; Canadá Fil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; Uruguay Fil: Perez Jiménez, J. C.. El Colegio de la Frontera del Sur; México Fil: Rincon, G.. Universidade Federal Do Maranhao.; Brasil Fil: Schneider, E. V. C.. Cape Eleuthera Institute; Bahamas Fil: Simpson, N. J.. Salvageblue; San Vicente y las Granadinas Fil: Talwar, B. S.. Florida International University; Estados Unidos Fil: Pollom, R.. University Fraser Simon; Canadá
- Published
- 2020
7. How does salinity tolerance influence the distributions of Brachionus plicatilis sibling species?
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Lowe, C. D., Kemp, S. J., Díaz-Avalos, C., and Montagnes, D. J. S.
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- 2007
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8. Primary Familial Hyperaldosteronism Type 1 in Hypertensive Children: Prevalence, Clinical and Biochemical Characteristics.
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Garcia, H, primary, Aglony, M, additional, Martinez, A, additional, Carvajal, C, additional, Campino, C, additional, Bolte, L, additional, Avalos, C, additional, Bancalari, R, additional, Loureiro, C, additional, Brinkman, K, additional, Giadrosich, V, additional, Mericq, V, additional, Rocha, A, additional, and Fardella, C, additional
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- 2010
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9. Determination of Aldosterone-to-Renin Ratio in Normotensive Pediatric Population To Be Used as Screening of Primary Hiperaldosteronism.
- Author
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Bancalari, R, primary, Aglony, M, additional, Martinez-Aguayo, A, additional, Campino, C, additional, Bolte, L, additional, Avalos, C, additional, Loureiro, C, additional, Carvajal, C, additional, Garcia, H, additional, and Fardella, C, additional
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- 2010
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10. Fast and Sensitive Detection of Paramagnetic Species Using Coupled Charge and Spin Dynamics in Strongly Fluorescent Nanodiamonds
- Author
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Gorrini, F., primary, Giri, R., additional, Avalos, C. E., additional, Tambalo, S., additional, Mannucci, S., additional, Basso, L., additional, Bazzanella, N., additional, Dorigoni, C., additional, Cazzanelli, M., additional, Marzola, P., additional, Miotello, A., additional, and Bifone, A., additional
- Published
- 2019
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11. A Deletion of More than 800 kb Is the Most Recurrent Mutation in Chilean Patients with SHOX Gene Defects
- Author
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Marcela Lagos, Andreina Cattani, Reyes L, Alejandro Martinez-Aguayo, Arriaza M, Hernan Garcia, Mariana Aracena, Cecilia Mellado, Vera A, H Rumié, Lacourt P, Teresa Aravena, Helena Poggi, Avalos C, Mericq, and Godoy C
- Subjects
Genetics ,Mutation ,education.field_of_study ,Langer mesomelic dysplasia ,Endocrinology, Diabetes and Metabolism ,Point mutation ,Haplotype ,Population ,Single-nucleotide polymorphism ,Biology ,medicine.disease_cause ,medicine.disease ,Short stature ,Endocrinology ,Pediatrics, Perinatology and Child Health ,medicine ,medicine.symptom ,Allele ,education - Abstract
Background: Deletions in the SHOX gene are the most frequent genetic cause of Leri-Weill syndrome and Langer mesomelic dysplasia, which are also present in idiopathic short stature. Aim: To describe the molecular and clinical findings observed in 23 of 45 non-consanguineous Chilean patients with different phenotypes related to SHOX deficiency. Methods: Multiplex ligation-dependent probe amplification was used to detect the deletions; the SHOX coding region and deletion-flanking areas were sequenced to identify point mutations and single-nucleotide polymorphisms (SNPs). Results: The main genetic defects identified in 21 patients consisted of deletions; one of them, a large deletion of >800 kb, was found in 8 patients. Also, a smaller deletion of >350 kb was observed in 4 patients. Although we could not precisely determine the deletion breakpoint, we were able to identify a common haplotype in 7 of the 8 patients with the larger deletion based on 22 informative SNPs. Conclusion: These results suggest that the large deletion-bearing allele has a common ancestor and was either introduced by European immigrants or had originated in our Amerindian population. This study allowed us to identify one recurrent deletion in Chilean patients; also, it contributed to expanding our knowledge about the genetic background of our population.
- Published
- 2015
12. Coupled charge and spin dynamics in high-density ensembles of nitrogen-vacancy centers in diamond
- Author
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Giri, R., primary, Gorrini, F., additional, Dorigoni, C., additional, Avalos, C. E., additional, Cazzanelli, M., additional, Tambalo, S., additional, and Bifone, A., additional
- Published
- 2018
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13. Variability of PM10 in industrialized-urban areas. New coefficients to establish significant differences between sampling points
- Author
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Vicente, A.B., primary, Juan, P., additional, Meseguer, S., additional, Díaz-Avalos, C., additional, and Serra, L., additional
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- 2018
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14. Macrophage A2A adenosinergic receptor modulates oxygen-induced augmentation of murine lung injury
- Author
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Garibaldi, B.T., Mock, J.R., Sidhaye, V., Avalos, C., Powell, J., Waickman, A.T., Polotsky, V.Y., Files, D.C., Chau, E., Eto, Y., D'Alessio, F.R., King, L.S., Aggarwal, N.R., and Horton, M.
- Abstract
Acute respiratory distress syndrome (ARDS) causes significant morbidity and mortality. Exacerbating factors increasing the risk of ARDS remain unknown. Supplemental oxygen is oftennecessary inbothmild and severe lung disease. The potential effects of supplemental oxygen may include augmentation of lung inflammation by inhibiting antiinflammatory pathways in alveolar macrophages. We sought to determine oxygen- derived effects on the anti-inflammatory A2A adenosinergic (ADORA2A) receptor in macrophages, and the role of the ADORA2A receptor in lung injury. Wild-type (WT) and ADORA2A-/- mice received intratracheal lipopolysaccharide (IT LPS), followed 12 hours later by continuous exposure to 21% oxygen (control mice) or 60% oxygenfor1to3days. Wemeasuredthephenotypic endpoints of lung injury and the alveolarmacrophage inflammatory state.We tested an ADORA2A-specific agonist, CGS-21680 hydrochloride, in LPS plus oxygen-exposed WT and ADORA2A-/- mice. We determined the specific effects of myeloid ADORA2A, using chimera experiments. Compared with WT mice, ADORA2A-/- mice exposed to IT LPS and 60%oxygen demonstrated significantly more histologic lung injury, alveolar neutrophils, and protein. Macrophages from ADORA2A-/- mice exposedto LPS plus oxygen expressed higher concentrations of proinflammatory cytokines and cosignaling molecules. CGS- 21680 prevented the oxygen-induced augmentation of lung injury after LPS only in WT mice. Chimera experiments demonstrated that the transfer of WT but not ADORA2A-/- bone marrow cells into irradiated ADORA2A-/- mice reduced lung injury after LPS plus oxygen, demonstrating myeloid ADORA2A protection. ADORA2A is protective against lung injury after LPS and oxygen. Oxygen after LPS increases macrophage activation to augment lung injury by inhibiting the ADORA2A pathway.
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- 2013
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15. ABSTRACT 579
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Acuna, J., primary, Arbo, A., additional, Lovera, D., additional, Ledesma, S., additional, Martinez de Cuellar, C., additional, Apodaca, S., additional, Avalos, C., additional, Mezquita, M., additional, Amarilla, S., additional, Aguiar, A., additional, and Golnzalez, N., additional
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- 2014
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16. Clinical characteristics of Dengue Shock Syndrome (DSS) in children
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Lovera, D., primary, Ledesma, S., additional, Avalos, C., additional, Amarilla, S., additional, Gonzalez, N., additional, Mezquita, M.J., additional, Araya, S., additional, Apodaca, S., additional, Aguiar, C., additional, Acuña, J., additional, Cuellar, C.M. Martínez de, additional, and Arbo, A., additional
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- 2014
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17. Consultorio escuela. El aprendizaje vinculado de la teoría con la práctica.
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Avalos-C., María Teresa, Amador-Olvera, Eric, and Zerón-Gutiérrez, Lydia
- Abstract
It is often said that it is easier to learn what is observed and practiced on a daily basis; to the need to effectively link theory with practice considered in the process of teaching and learning, many strategies have been developed to allow this process to be carried out in a more efficiently maner. It is, therefore, very important to recognize that an appropriate teacher/student relationship is essential for students to acquire the skills and abilities required. [ABSTRACT FROM AUTHOR]
- Published
- 2016
18. How does salinity tolerance influence the distributions of Brachionus plicatilis sibling species?
- Author
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Lowe, C. D., primary, Kemp, S. J., additional, Díaz-Avalos, C., additional, and Montagnes, D. J. S., additional
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- 2006
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19. Spatial structure of planktonic ciliate patches in a tropical coastal lagoon: an application of geostatistical methods
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Bulit, C, primary, Díaz-Avalos, C, additional, Signoret, M, additional, and Montagnes, DJS, additional
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- 2003
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20. Determinación toxicológica de Cocaína, Marihuana y sus metabolitos en escolares de Educación Secundaria en Lima-Perú
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Anaya P., Rosalía, primary, Chincayán R., Mauro, primary, Guerra C., José, primary, Aguirre Q., Mario, primary, Darg B., Alicia, primary, Tarazona J., Wilmer, primary, Cárdenas R., Erika R., primary, Monteviller S., Daniel, primary, Valentin A., Edgard F., primary, Solorzano O., Martha, primary, Capillo R., July M., primary, Guillén C., Julio C., primary, Guerra, Henry, primary, Parra, Lutter, primary, Saldaña P., Rita M., primary, Mamani C., César, primary, Coronado F., Edwin, primary, Retuerto F., Mónica G., primary, Alvarado H., Mabel, primary, Caballero D., Raquel, primary, Medina C., Rosana, primary, Chirinos, Carmen, primary, Córdova A., Patricia, primary, Apesteguía I., Alfonso, primary, Avalos C., Ernesto, primary, Mamaní M., Raúl, primary, Pillco V., Jesús, primary, Araujo, José, primary, and Torres R., Manuel, primary
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- 2000
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21. 1-29-05 Autosomic dominant cerebellar ataxia associated with mitral valve propapse
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Castañeda, M.A., primary, Ptaceck, L., additional, Shibao, H., additional, Armas, J., additional, Quiroz, E., additional, Polanco, T., additional, Avalos, C., additional, and Jerí, F.R., additional
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- 1997
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22. Differences in Response Between 18 Carbon Fatty Acids and 12/14 Carbon Saturated Fatty Acids on Plasma Cholesterol in Guinea Pigs
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Fernandez, M. L., Avalos, C., and Vergara-Jimenez, M.
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- 1998
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23. Face time with HQ.
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Foltin N, Goulart JC, Avalos C, and Rein A
- Published
- 2010
24. Organ-specific immune setpoints underlie divergent immune profiles across metastatic sites in breast cancer.
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Egelston CA, Guo W, Simons DL, Ye J, Avalos C, Solomon ST, Nwangwu M, Nelson MS, Tan J, Bacon ER, Ihle K, Schmolze D, Tumyan L, Waisman JR, and Lee PP
- Abstract
Immune composition within the tumor microenvironment (TME) plays a central role in the propensity of cancer to metastasize and to respond to therapy. Previous studies suggested that the metastatic TME is immune suppressed. However, limited accessibility to multiple metastatic sites within patients has made assessment of the immune TME in the context of multi-organ metastases difficult. We utilized a rapid postmortem tissue collection protocol to assess immune composition in numerous sites of breast cancer metastasis and paired tumor-free tissues. Metastases were found to have comparable immune cell densities and composition to paired tumor-free tissues of the same organ type. In contrast, immune cell densities in both metastatic and tumor-free tissues were significantly different between organ types, with lung immune infiltration consistently greater than liver. These immune profiling results were consistent between both flow cytometry and multiplex immunofluorescence-based spatial analysis. Furthermore, we found granulocytes were a predominant tumor-infiltrating immune cell in both lung and liver metastases and these granulocytes made up the majority of PD-L1-expressing cells in many tissue sites. We also identified distinct potential mechanisms of immunosuppression in lung and liver metastases, with lung having increased expression of PD-L1+ antigen-presenting cells and liver having higher numbers of activated regulatory T cells and HLA-DRlow monocytes. Together these results demonstrate that immune contexture of metastases is dictated by organ type, and that immunotherapy strategies may benefit from unique tailoring to tissue-specific features of the immune TME.
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- 2024
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25. A New Method for Low Density Distribution Modeling and Near Threatened Species: The Study Case of Plectrohyla Guatemalensis.
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Ballesteros M, Díaz-Avalos C, Hernández O, and Garro G
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- Animals, Mexico, Guatemala, Anura physiology, Ecosystem, Animal Distribution, Population Dynamics statistics & numerical data, Endangered Species statistics & numerical data, Mathematical Concepts, Models, Biological, Conservation of Natural Resources statistics & numerical data, Markov Chains, Population Density
- Abstract
We introduce a model that can be used for the description of the distribution of species when there is scarcity of data, based on our previous work (Ballesteros et al. J Math Biol 85(4):31, 2022). We address challenges in modeling species that are seldom observed in nature, for example species included in The International Union for Conservation of Nature's Red List of Threatened Species (IUCN 2023). We introduce a general method and test it using a case study of a near threatened species of amphibians called Plectrohyla Guatemalensis (see IUCN 2023) in a region of the UNESCO natural reserve "Tacaná Volcano", in the border between Mexico and Guatemala. Since threatened species are difficult to find in nature, collected data can be extremely reduced. This produces a mathematical problem in the sense that the usual modeling in terms of Markov random fields representing individuals associated to locations in a grid generates artificial clusters around the observations, which are unreasonable. We propose a different approach in which our random variables describe yearly averages of expectation values of the number of individuals instead of individuals (and they take values on a compact interval). Our approach takes advantage of intuitive insights from environmental properties: in nature individuals are attracted or repulsed by specific features (Ballesteros et al. J Math Biol 85(4):31, 2022). Drawing inspiration from quantum mechanics, we incorporate quantum Hamiltonians into classical statistical mechanics (i.e. Gibbs measures or Markov random fields). The equilibrium between spreading and attractive/repulsive forces governs the behavior of the species, expressed through a global control problem involving an energy operator., (© 2024. The Author(s).)
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- 2024
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26. Cerebral organoids display dynamic clonal growth and tunable tissue replenishment.
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Lindenhofer D, Haendeler S, Esk C, Littleboy JB, Brunet Avalos C, Naas J, Pflug FG, van de Ven EGP, Reumann D, Baffet AD, von Haeseler A, and Knoblich JA
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- Humans, Brain cytology, Brain growth & development, Brain metabolism, Cell Differentiation, Cell Proliferation, Clone Cells, Neurogenesis genetics, DNA Barcoding, Taxonomic, Animals, Organoids cytology, Organoids metabolism, Cell Lineage, Neural Stem Cells metabolism, Neural Stem Cells cytology
- Abstract
During brain development, neural progenitors expand through symmetric divisions before giving rise to differentiating cell types via asymmetric divisions. Transition between those modes varies among individual neural stem cells, resulting in clones of different sizes. Imaging-based lineage tracing allows for lineage analysis at high cellular resolution but systematic approaches to analyse clonal behaviour of entire tissues are currently lacking. Here we implement whole-tissue lineage tracing by genomic DNA barcoding in 3D human cerebral organoids, to show that individual stem cell clones produce progeny on a vastly variable scale. By using stochastic modelling we find that variable lineage sizes arise because a subpopulation of lineages retains symmetrically dividing cells. We show that lineage sizes can adjust to tissue demands after growth perturbation via chemical ablation or genetic restriction of a subset of cells in chimeric organoids. Our data suggest that adaptive plasticity of stem cell populations ensures robustness of development in human brain organoids., (© 2024. The Author(s).)
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- 2024
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27. A cell fate decision map reveals abundant direct neurogenesis bypassing intermediate progenitors in the human developing neocortex.
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Coquand L, Brunet Avalos C, Macé AS, Farcy S, Di Cicco A, Lampic M, Wimmer R, Bessières B, Attie-Bitach T, Fraisier V, Sens P, Guimiot F, Brault JB, and Baffet AD
- Subjects
- Humans, Cell Differentiation, Ependymoglial Cells cytology, Ependymoglial Cells metabolism, Receptors, Notch metabolism, Receptors, Notch genetics, Cell Division, Cell Proliferation, Neocortex cytology, Neocortex embryology, Neocortex metabolism, Neurogenesis, Organoids cytology, Organoids metabolism, Neural Stem Cells cytology, Neural Stem Cells metabolism, Cell Lineage
- Abstract
The human neocortex has undergone strong evolutionary expansion, largely due to an increased progenitor population, the basal radial glial cells. These cells are responsible for the production of a diversity of cell types, but the successive cell fate decisions taken by individual progenitors remain unknown. Here we developed a semi-automated live/fixed correlative imaging method to map basal radial glial cell division modes in early fetal tissue and cerebral organoids. Through the live analysis of hundreds of dividing progenitors, we show that basal radial glial cells undergo abundant symmetric amplifying divisions, and frequent self-consuming direct neurogenic divisions, bypassing intermediate progenitors. These direct neurogenic divisions are more abundant in the upper part of the subventricular zone. We furthermore demonstrate asymmetric Notch activation in the self-renewing daughter cells, independently of basal fibre inheritance. Our results reveal a remarkable conservation of fate decisions in cerebral organoids, supporting their value as models of early human neurogenesis., (© 2024. The Author(s).)
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- 2024
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28. P2X7 Receptor in Dendritic Cells and Macrophages: Implications in Antigen Presentation and T Lymphocyte Activation.
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Acuña-Castillo C, Escobar A, García-Gómez M, Bachelet VC, Huidobro-Toro JP, Sauma D, and Barrera-Avalos C
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- Lymphocyte Activation, Macrophages, Dendritic Cells, Receptors, Purinergic P2X7, Antigen Presentation
- Abstract
The P2X7 receptor, a member of the P2X purinergic receptor family, is a non-selective ion channel. Over the years, it has been associated with various biological functions, from modulating to regulating inflammation. However, its emerging role in antigen presentation has captured the scientific community's attention. This function is essential for the immune system to identify and respond to external threats, such as pathogens and tumor cells, through T lymphocytes. New studies show that the P2X7 receptor is crucial for controlling how antigens are presented and how T cells are activated. These studies focus on antigen-presenting cells, like dendritic cells and macrophages. This review examines how the P2X7 receptor interferes with effective antigen presentation and activates T cells and discusses the fundamental mechanisms that can affect the immune response. Understanding these P2X7-mediated processes in great detail opens up exciting opportunities to create new immunological therapies.
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- 2024
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29. A retrospective study suggests 55 days of persistence of SARS-CoV-2 during the first wave of the pandemic in Santiago de Chile.
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Acuña-Castillo C, Vidal M, Vallejos-Vidal E, Luraschi R, Barrera-Avalos C, Inostroza-Molina A, Molina-Cabrera S, Valdes D, Schafer C, Maisey K, Imarai M, Vera R, Vargas S, Rojo LE, Leiva-Salcedo E, Escobar A, Reyes-Cerpa S, Gaete A, Palma-Vejares R, Travisany D, Torres C, Reyes-López FE, and Sandino AM
- Abstract
Background: As the COVID-19 pandemic persists, infections continue to surge globally. Presently, the most effective strategies to curb the disease and prevent outbreaks involve fostering immunity, promptly identifying positive cases, and ensuring their timely isolation. Notably, there are instances where the SARS-CoV-2 virus remains infectious even after patients have completed their quarantine., Objective: Understanding viral persistence post-quarantine is crucial as it could account for localized infection outbreaks. Therefore, studying and documenting such instances is vital for shaping future public health policies., Design: This study delves into a unique case of SARS-CoV-2 persistence in a 60-year-old female healthcare worker with a medical history of hypertension and hypothyroidism. The research spans 55 days, marking the duration between her initial and subsequent diagnosis during Chile's first COVID-19 wave, with the analysis conducted using RT-qPCR., Results: Genomic sequencing-based phylogenetic analysis revealed that the SARS-CoV-2 detected in both Nasopharyngeal swab samples (NPSs) was consistent with the 20B clade of the Nextstrain classification, even after a 55-day interval., Conclusion: This research underscores the need for heightened vigilance concerning cases of viral persistence. Such instances, albeit rare, might be pivotal in understanding sporadic infection outbreaks that occur post-quarantine., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Published by Elsevier Ltd.)
- Published
- 2024
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30. Selenoprotein deficiency disorder predisposes to aortic aneurysm formation.
- Author
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Schoenmakers E, Marelli F, Jørgensen HF, Visser WE, Moran C, Groeneweg S, Avalos C, Jurgens SJ, Figg N, Finigan A, Wali N, Agostini M, Wardle-Jones H, Lyons G, Rusk R, Gopalan D, Twiss P, Visser JJ, Goddard M, Nashef SAM, Heijmen R, Clift P, Sinha S, Pirruccello JP, Ellinor PT, Busch-Nentwich EM, Ramirez-Solis R, Murphy MP, Persani L, Bennett M, and Chatterjee K
- Subjects
- Humans, Male, Mice, Animals, Selenocysteine, Muscle, Smooth, Vascular metabolism, Selenoproteins genetics, Myocytes, Smooth Muscle metabolism, Zebrafish, Aortic Aneurysm genetics, Aortic Aneurysm metabolism
- Abstract
Aortic aneurysms, which may dissect or rupture acutely and be lethal, can be a part of multisystem disorders that have a heritable basis. We report four patients with deficiency of selenocysteine-containing proteins due to selenocysteine Insertion Sequence Binding Protein 2 (SECISBP2) mutations who show early-onset, progressive, aneurysmal dilatation of the ascending aorta due to cystic medial necrosis. Zebrafish and male mice with global or vascular smooth muscle cell (VSMC)-targeted disruption of Secisbp2 respectively show similar aortopathy. Aortas from patients and animal models exhibit raised cellular reactive oxygen species, oxidative DNA damage and VSMC apoptosis. Antioxidant exposure or chelation of iron prevents oxidative damage in patient's cells and aortopathy in the zebrafish model. Our observations suggest a key role for oxidative stress and cell death, including via ferroptosis, in mediating aortic degeneration., (© 2023. The Author(s).)
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- 2023
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31. An ecological study on reinfection rates using a large dataset of RT-qPCR tests for SARS-CoV-2 in Santiago of Chile.
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Acuña-Castillo C, Barrera-Avalos C, Bachelet VC, Milla LA, Inostroza-Molina A, Vidal M, Luraschi R, Vallejos-Vidal E, Mella-Torres A, Valdés D, Reyes-López FE, Imarai M, Rojas P, and Sandino AM
- Subjects
- Humans, Female, Adult, Middle Aged, Chile epidemiology, Reinfection epidemiology, SARS-CoV-2 genetics, COVID-19 diagnosis, COVID-19 epidemiology
- Abstract
Introduction: As the SARS-CoV-2 continues to evolve, new variants pose a significant threat by potentially overriding the immunity conferred by vaccination and natural infection. This scenario can lead to an upswing in reinfections, amplified baseline epidemic activity, and localized outbreaks. In various global regions, estimates of breakthrough cases associated with the currently circulating viral variants, such as Omicron, have been reported. Nonetheless, specific data on the reinfection rate in Chile still needs to be included., Methods: Our study has focused on estimating COVID-19 reinfections per wave based on a sample of 578,670 RT-qPCR tests conducted at the University of Santiago of Chile (USACH) from April 2020 to July 2022, encompassing 345,997 individuals., Results: The analysis reveals that the highest rate of reinfections transpired during the fourth and fifth COVID-19 waves, primarily driven by the Omicron variant. These findings hold despite 80% of the Chilean population receiving complete vaccination under the primary scheme and 60% receiving at least one booster dose. On average, the interval between initial infection and reinfection was found to be 372 days. Interestingly, reinfection incidence was higher in women aged between 30 and 55. Additionally, the viral load during the second infection episode was lower, likely attributed to Chile's high vaccination rate., Discussion: This study demonstrates that the Omicron variant is behind Chile's highest number of reinfection cases, underscoring its potential for immune evasion. This vital epidemiological information contributes to developing and implementing effective public health policies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Acuña-Castillo, Barrera-Avalos, Bachelet, Milla, Inostroza-Molina, Vidal, Luraschi, Vallejos-Vidal, Mella-Torres, Valdés, Reyes-López, Imarai, Rojas and Sandino.)
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- 2023
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32. Cardiac Tamponade as a Complication of Microscopic Polyangiitis: A Case Associated With a COVID-19 mRNA Vaccine.
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Avalos C, Ahmadzadeh Y, Gatsak D, Moosa SA, Mozaffari MA, Imas AS, and Miller R
- Abstract
Widespread uptake of the coronavirus disease 2019 (COVID-19) vaccinations has become the world's championed defense against the global pandemic. Four vaccines have been either approved or authorized for emergency use by the FDA, and at this time, over 13 billion doses of these vaccines have been administered around the world. Unfortunately, uncommon and sometimes unforeseen side effects such as small-vessel vasculitis have been reported. In this case report, we present a 74-year-old woman with a history of hypertension, type 2 diabetes mellitus, and hypothyroidism who developed microscopic polyangiitis (MPA) following the second dose of the Pfizer-BioNTech mRNA vaccine for COVID-19. The diagnosis of MPA was confirmed by a kidney biopsy. The autoimmune condition progressed to pericardial effusion and eventual cardiac tamponade, which is occasionally seen in the disease. In this patient's case, we suspect there to be a temporal association between mRNA COVID-19 vaccination and the development of MPA. Direct causation has not been determined., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Avalos et al.)
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- 2023
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33. Biomarkers for dementia in Latin American countries: Gaps and opportunities.
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Parra MA, Orellana P, Leon T, Victoria CG, Henriquez F, Gomez R, Avalos C, Damian A, Slachevsky A, Ibañez A, Zetterberg H, Tijms BM, Yokoyama JS, Piña-Escudero SD, Cochran JN, Matallana DL, Acosta D, Allegri R, Arias-Suárez BP, Barra B, Behrens MI, Brucki SMD, Busatto G, Caramelli P, Castro-Suarez S, Contreras V, Custodio N, Dansilio S, la Cruz-Puebla M, de Souza LC, Diaz MM, Duque L, Farías GA, Ferreira ST, Guimet NM, Kmaid A, Lira D, Lopera F, Meza BM, Miotto EC, Nitrini R, Nuñez A, O'Neill S, Ochoa J, Pintado-Caipa M, Resende EPF, Risacher S, Rojas LA, Sabaj V, Schilling L, Sellek AF, Sosa A, Takada LT, Teixeira AL, Unaucho-Pilalumbo M, and Duran-Aniotz C
- Subjects
- Humans, Latin America, Dementia diagnosis
- Abstract
Limited knowledge on dementia biomarkers in Latin American and Caribbean (LAC) countries remains a serious barrier. Here, we reported a survey to explore the ongoing work, needs, interests, potential barriers, and opportunities for future studies related to biomarkers. The results show that neuroimaging is the most used biomarker (73%), followed by genetic studies (40%), peripheral fluids biomarkers (31%), and cerebrospinal fluid biomarkers (29%). Regarding barriers in LAC, lack of funding appears to undermine the implementation of biomarkers in clinical or research settings, followed by insufficient infrastructure and training. The survey revealed that despite the above barriers, the region holds a great potential to advance dementia biomarkers research. Considering the unique contributions that LAC could make to this growing field, we highlight the urgent need to expand biomarker research. These insights allowed us to propose an action plan that addresses the recommendations for a biomarker framework recently proposed by regional experts., (© 2022 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)
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- 2023
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34. Genomic Evidence Suggests Viral Persistence of SARS-CoV-2 for 386 Days in Health Worker: A Case Report from Santiago of Chile.
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Acuña-Castillo C, Maisey K, Vidal M, Barrera-Avalos C, Inostroza-Molina A, Luraschi R, Vallejos-Vidal E, Valdés D, Imarai M, Reyes-López FE, and Sandino AM
- Abstract
The COVID-19 pandemic continues to affect several countries. One of the best ways to control its spread is the timely identification of infected patients for isolation and quarantine. While an episode of infection lasts an average of 8-10 days from the onset of symptoms, there is literature describing long-lasting viral persistence events. Here, we report a case of persistence of SARS-CoV-2 for 386 days in a health worker from Santiago de Chile. Our study could be one of the longest reported viral persistence events. RNA sequencing analyses indicated that the first positive diagnosis (8 June 2020) corresponded to a SARS-CoV-2 variant belonging to Clade Nextstrain 20A. Three hundred eighty-six days later (23 September 2021), the second positive result reached the same viral variant (Clade 20A) but without presence or circulation in Chile since May 2021. Both sequencing coverages showed an identity of 99.21%, with some mutations related to the severity of the disease (ORF1b:P314L) and more infectivity (S:D614G). This work reinforces the idea of implementing an RT-qPCR or rapid antigen test once the quarantine is fulfilled to ensure viral absence, identify potential persistence, and, consequently, minimize the risk of local outbreaks of SARS-CoV-2 infection.
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- 2022
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35. Evaluation and comparison of the sensitivity of three commercial RT-qPCR kits used for the detection of SARS-CoV-2 in Santiago, Chile.
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Luraschi R, Santibáñez Á, Barrera-Avalos C, Vallejos-Vidal E, Mateluna-Flores C, Alarcón J, Cayunao J, Mella-Torres A, Hernández F, Inostroza-Molina A, Valdés D, Imarai M, Acuña-Castillo C, Reyes-López FE, and Sandino AM
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- Humans, Pandemics, Chile, Nasopharynx, RNA, Viral genetics, RNA, Viral analysis, Sensitivity and Specificity, SARS-CoV-2 genetics, COVID-19 diagnosis
- Abstract
Introduction: The COVID-19 pandemic is still in force, causing global public health challenges and threats. Although vaccination and herd immunity have proven to be the most efficient way to control the pandemic, massive and early testing of patients using the RT-qPCR technique is crucial for constant genomic surveillance. The appearance of variants of SARS-CoV-2 with new mutations can reduce the efficiency of diagnostic detection. In this sense, several commercial RT-qPCR kits have been the target of extensive analysis because low assay performance could lead to false-negative diagnoses., Methods: In this study, we evaluated the performance of three commercial RT-qPCR kits; Thermo Fisher (TaqMan 2019-nCoV Assay Kit v1), BGI and Roche (LightCycler
® Multiplex RNA Virus Master) used for the diagnosis of COVID-19 throughout the pandemic in Santiago de Chile., Results: Under our best assay conditions, we found significant differences in Cq amplification values for control and viral probes, against the same nasopharyngeal swab samples (NPSs). In addition, in some cases, the sensitivity of the RT-qPCR kits decreased against viral variants., Conclusion: Our study suggests evaluating the RT-qPCR kits used to detect SARS-CoV-2 because variants such as Omicron, which has several mutations, can compromise their detection and underestimate viral circulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Luraschi, Santibáñez, Barrera-Avalos, Vallejos-Vidal, Mateluna-Flores, Alarcón, Cayunao, Mella-Torres, Hernández, Inostroza-Molina, Valdés, Imarai, Acuña-Castillo, Reyes-López and Sandino.)- Published
- 2022
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36. Epidemiological characteristics of Omicron and Delta SARS-CoV-2 variant infection in Santiago, Chile.
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Mella-Torres A, Escobar A, Barrera-Avalos C, Vargas-Salas S, Pirazzoli M, Gonzalez U, Valdes D, Rojas P, Luraschi R, Vallejos-Vidal E, Imarai M, Sandino AM, Reyes-López FE, Vera R, and Acuña-Castillo C
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- Humans, Chile epidemiology, Pandemics, SARS-CoV-2, COVID-19 epidemiology
- Abstract
The variant of concern (VOC) SARS-CoV-2 Omicron (B.1.1529) has been described as a highly contagious variant but less virulent than the current variant being monitored (VBM) Delta (B.1.617.2), causing fewer cases of hospitalizations, symptomatology, and deaths associated with COVID-19 disease. Although the epidemiological comparison of both variants has been previously reported in other countries, no report indicates their behavior and severity of infection in Chile. In this work, we report for the first time the effect of the Omicron and Delta variants in a cohort of 588 patients from the Hospital de Urgencia Asistencia pública (HUAP), a high-complexity health center in Santiago, Chile. This report is framed at the beginning of Chile's third wave of the COVID-19 pandemic, with a marked increase in the Omicron variant and a decrease in the circulating Delta variant. Our results indicated a similar proportion of patients with a complete vaccination schedule for both variants. However, the Delta variant was associated with a higher prevalence of hospitalization and more significant symptomatology associated with respiratory distress. On the other hand, our data suggest that vaccination is less effective in preventing infection by the Omicron variant. This antecedent, with a low severity but high contagiousness, suggests that the Omicron variant could even collapse the primary health care service due to the high demand for health care., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Mella-Torres, Escobar, Barrera-Avalos, Vargas-Salas, Pirazzoli, Gonzalez, Valdes, Rojas, Luraschi, Vallejos-Vidal, Imarai, Sandino, Reyes-López, Vera and Acuña-Castillo.)
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- 2022
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37. Sensitivity analysis of rapid antigen tests for the Omicron SARS-CoV-2 variant detection from nasopharyngeal swab samples collected in Santiago of Chile.
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Barrera-Avalos C, Mena J, Luraschi R, Rojas P, Mateluna-Flores C, Vallejos-Vidal E, Imarai M, Sandino AM, Valdés D, Vera R, Hernández I, Reyes-López FE, and Acuña-Castillo C
- Subjects
- Humans, Pandemics, Chile, Sensitivity and Specificity, Nasopharynx, SARS-CoV-2 genetics, COVID-19 diagnosis
- Abstract
The COVID-19 pandemic continues to be a concern and keeps global health authorities on alert. The RT-PCR technique has been the gold-standard assay for detecting the SARS-CoV-2 virus. However, rapid antigen tests (RATs) have been widely used to increase the number of tests faster and more efficiently in the population. Nevertheless, the appearance of new viral variants, with genomic mutations associated with greater contagiousness and immune evasion, highlights the need to evaluate the sensitivity of these RATs. This report evaluates the sensitivity of SD Biosensor-Roche, Panbio™, and Clinitest® RATs widely used in Santiago de Chile in the detection of the Omicron variant from Nasopharyngeal samples (NPSs), the most predominant SARS-CoV-2 variant in Chile and the world. SD Biosensor-Roche shows a detection sensitivity of 95.7% in the viral amplification range of 20 ≤ Cq < 25, while Panbio™ and Clinitest® show 100% and 91.3%, respectively. In the viral amplification ranges of 25 ≤ Cq < 30, the detection sensitivity decreased to 28% for SD Biosensor-Roche, 32% for Panbio™, and 72% for Clinitest®. This study indicates that the tested RATs have high sensitivity in detecting the Omicron variant of concern (VOC) at high viral loads. By contrast, its sensitivity decreases at low viral loads. Therefore, it is suggested to limit the use of RATs as an active search method, considering that infections in patients are increasingly associated with lower viral loads of SARS-CoV-2. These antecedents could prevent contagion outbreaks and reduce the underestimation of the current Omicron variant circulation at the local level., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barrera-Avalos, Mena, Luraschi, Rojas, Mateluna-Flores, Vallejos-Vidal, Imarai, Sandino, Valdés, Vera, Hernández, Reyes-López and Acuña-Castillo.)
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- 2022
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38. Autoimmune Encephalopathy Associated With Anti-thyroid Antibodies: A Case Report.
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Falb V, Costanzo L, Avalos C, and Feoktistov A
- Abstract
Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), also known as Hashimoto encephalopathy (HE), is a rare condition. HE is characterized by abnormal brain function associated with elevated titers of anti-thyroid peroxidase (anti-TPO) and/or anti-thyroglobulin (anti-Tg) antibodies. We present a case of a 19-year-old female with rapidly progressing psychosis with mutism, catalepsy, echopraxia, and catatonia that developed over the course of three months. She was found to have high-level anti-thyroid antibodies raising suspicion of subclinical autoimmune thyroiditis and positive antinuclear antibodies. Imaging of the brain revealed generalized cerebral atrophy abnormal for her age. The patient was aggressively treated with corticosteroids and immunomodulators and her symptoms were greatly improved. This case emphasizes the significance of thyroid antibody measurement in patients presenting with psychiatric symptoms to evaluate patients for autoimmune encephalitis, since treatment with steroids and other immunosuppressive agents may be warranted., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Falb et al.)
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- 2022
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39. The Comparative Analysis of Two RT-qPCR Kits for Detecting SARS-CoV-2 Reveals a Higher Risk of False-Negative Diagnosis in Samples with High Quantification Cycles for Viral and Internal Genes.
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Luraschi R, Barrera-Avalos C, Vallejos-Vidal E, Alarcón J, Mella-Torres A, Hernández F, Inostroza-Molina A, Valdés D, Imarai M, Acuña-Castillo C, Reyes-López FE, and Sandino AM
- Abstract
The early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the real-time quantitative polymerase chain reaction (RT-qPCR) as a gold-standard molecular tool has allowed to test and trace the viral spread and the isolation of COVID-19-infected patients. The detection capacity of viral and internal genes is an essential parameter to consider and analyze during the assay. In this study, we analyze the performance of the two commercial RT-qPCR kits used in Chile, TaqMan™ 2019-nCoV Control Kit v1 (Thermo Fisher) and MaxCov19 (TAAG Genetics), for the COVID-19 diagnosis from nasopharyngeal swab samples (NPSs). Our results show a lower sensitivity of the TAAG kit compared to the Thermo Fisher kit, even in the detection of SARS-CoV-2 mutations associated with its variants. This study reinforces the relevance of evaluating the performance of RT-qPCR kits before being used massively since those with lower sensitivity can generate false negatives and produce outbreaks of local infections., Competing Interests: All 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 Roberto Luraschi et al.)
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- 2022
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40. Comparison of the First and Second Wave of Infections by SARS-CoV-2: A Retrospective and Longitudinal Study From a Primary Health Care Center in Santiago of Chile.
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Acuña-Castillo C, Inostroza-Molina A, Castro SA, Molina-Cabrera S, Leiva-Salcedo E, Riquelme D, Luraschi R, Barrera-Avalos C, Vallejos-Vidal E, Mella-Torres A, Valdés D, Torres C, Maisey K, Escobar A, Reyes-Cerpa S, Toro-Ascuy D, Imarai M, Reyes-López FE, and Sandino AM
- Subjects
- Chile epidemiology, Humans, Longitudinal Studies, Pandemics, Primary Health Care, Retrospective Studies, COVID-19 epidemiology, SARS-CoV-2
- Abstract
The current COVID-19 pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Many countries have reported the experience of at least two contagion waves, describing associated mortality rates and population behavior. The analysis of the effect of this pandemic in different localities can provide valuable information on the key factors to consider in the face of future massive infectious diseases. This work describes the first retrospective and comparative study about behavior during the first and second waves of the COVID-19 pandemic in Chile from a primary Healthcare Center. From 19,313 real-time quantitative PCR (RT-qPCR) tests assessed, the selected 1,694 positive diagnostics showed a decrease in mortality rate in the second wave (0.6%) compared with the first (4.6%). In addition, we observed that infections in the second wave were mainly in young patients with reduced comorbidities. The population with a complete vaccination schedule shows a decrease in the duration of symptoms related to the disease, and patients with more comorbidities tend to develop severe illness. This report provides evidence to partially understand the behavior and critical factors in the severity of the COVID-19 pandemic in the population of Santiago of Chile., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Acuña-Castillo, Inostroza-Molina, Castro, Molina-Cabrera, Leiva-Salcedo, Riquelme, Luraschi, Barrera-Avalos, Vallejos-Vidal, Mella-Torres, Valdés, Torres, Maisey, Escobar, Reyes-Cerpa, Toro-Ascuy, Imarai, Reyes-López and Sandino.)
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- 2022
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41. First Identification of Reinfection by a Genetically Different Variant of SARS-CoV-2 in a Homeless Person from the Metropolitan Area of Santiago, Chile.
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Acuña-Castillo C, Vidal M, Inostroza-Molina A, Vallejos-Vidal E, Luraschi R, Figueroa M, Barrera-Avalos C, Vera R, Vargas S, Valdes D, Maisey K, Imarai M, Leiva-Salcedo E, Escobar A, Reyes-Cerpa S, Gaete A, Palma-Vejares R, Travisany D, Rojo LE, Reyes-López FE, and Sandino AM
- Subjects
- COVID-19 Testing, Chile epidemiology, Humans, Pandemics, Reinfection, SARS-CoV-2 genetics, COVID-19 epidemiology, Ill-Housed Persons
- Abstract
The identification and tracking of SARS-CoV-2 infected patients in the general population are essential components of the global strategy to limit the COVID-19 viral spread, specifically for maintaining traceability and suppressing the resurgence of local outbreaks. Public health programs that include continuous RT-qPCR testing for COVID-19 in the general population, viral sequencing, and genomic surveillance for highly contagious forms of the virus have allowed for the identification of SARS-CoV-2 infections and reinfections. This work identified SARS-CoV-2 reinfection in a homeless person, which occurred 58 days after the first COVID-19 diagnosis. Genomic sequencing identified a different Nextstrain classification clade (20A and 20B) and PANGO lineage, with a divergence of 4 single nucleotide variants (SNVs) in S and ORF1ab genes, suggesting reinfection by different viral variants. This study is the first from the great metropolitan area of Santiago, Chile, one of the top ten countries in the world to live during the COVID-19 pandemic. We support the importance of performing intensive genomic surveillance programs in the whole population and high-risk groups, such as homeless people, nearly 20 thousand people in Chile, and have limited access to health care services and poor viral traceability., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Claudio Acuña-Castillo et al.)
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- 2022
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42. Adverse Childhood Experiences and Subjective Cognitive Decline in the US.
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Brown MJ, Kaur A, James T, Avalos C, Addo PNO, Crouch E, and Hill NL
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- Behavioral Risk Factor Surveillance System, Humans, Sexual Behavior, Adverse Childhood Experiences, Cognitive Dysfunction epidemiology
- Abstract
Objective: The aim of this study was to determine the association between adverse childhood experiences (ACEs) and subjective cognitive decline (SCD) among a representative sample of the adult US population., Methods: Data were obtained from the 2019 Behavioral Risk Factor Surveillance System ( N = 82,688, ≥45 years). Adverse childhood experiences included sexual, physical/psychological and environmental ACEs, and a score. Multivariable logistic regression was used to determine the association between ACEs and SCD, and SCD-related outcomes., Results: Sexual (adjusted OR (aOR: 2.83; 95% CI: 2.42-3.31)), physical/psychological (aOR: 2.05; 95% CI: 1.83-2.29), and environmental (aOR: 1.94; 95% CI: 1.74-2.16) ACEs were associated with SCD in the past year. There was also a dose-response relationship between ACE score and SCD., Conclusion: ACEs were associated with SCD. Interventions to maximize cognitive health in aging and prevent future cognitive impairment should consider the potential role of ACEs among affected populations.
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- 2022
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43. Synthesis of BiOI/Mordenite Composites for Photocatalytic Treatment of Organic Pollutants Present in Agro-Industrial Wastewater.
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Gallegos-Alcaíno A, Robles-Araya N, Avalos C, Alfonso-Alvarez A, Rodríguez CA, Valdés H, Sánchez-Flores NA, Durán-Alvarez JC, Bizarro M, Romero-Salguero FJ, and Mera AC
- Abstract
Recently, bismuth oxyiodide (BiOI) is an attractive semiconductor to use in heterogeneous photocatalysis processes. Unfortunately, BiOI individually shows limited photocatalytic efficiency, instability, and a quick recombination of electron/holes. Considering the practical application of this semiconductor, some studies show that synthetic zeolites provide good support for this photocatalyst. This support material permits a better photocatalytic efficiency because it prevents the quick recombination of photogenerated pairs. However, the optimal conditions (time and temperature) to obtain composites (BiOI/ synthetic zeolite) with high photocatalytic efficiency using a coprecipitation-solvothermal growth method have not yet been reported. In this study, a response surface methodology (RSM) based on a central composite design (CCD) was applied to optimize the synthesis conditions of BiOI/mordenite composites. For this purpose, eleven BiOI/mordenite composites were synthesized using a combined coprecipitation-solvothermal method under different time and temperature conditions. The photocatalytic activities of the synthesized composites were evaluated after 20 min of photocatalytic oxidation of caffeic acid, a typical organic pollutant found in agro-industrial wastewater. Moreover, BiOI/mordenite composites with the highest and lowest photocatalytic activity were physically and chemically characterized using nitrogen adsorption isotherms, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and diffuse reflectance spectroscopy (DRS). The optimal synthesis conditions prove to be 187 °C and 9 h. In addition, the changes applied to the experimental conditions led to surface property modifications that influenced the photocatalytic degradation efficiency of the BiOI/mordenite composite toward caffeic acid photodegradation.
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- 2022
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44. Description of Symptoms Caused by the Infection of the SARS-CoV-2 B.1.621 (Mu) Variant in Patients With Complete CoronaVac Vaccination Scheme: First Case Report From Santiago of Chile.
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Barrera-Avalos C, Luraschi R, Acuña-Castillo C, Vidal M, Mella-Torres A, Inostroza-Molina A, Vera R, Vargas S, Hernández I, Perez C, Vallejos-Vidal E, Valdés D, Imarai M, Reyes-López FE, and Sandino AM
- Subjects
- Aged, Aged, 80 and over, COVID-19 Vaccines, Chile, Humans, SARS-CoV-2, Vaccination, COVID-19, Vaccines
- Abstract
Vaccine administration is one of the most efficient ways to control the current coronavirus disease 2019 (COVID-19) pandemic. However, the appearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants can avoid the immunity generated by vaccines. Thus, in patients with a complete vaccine schedule, the infection by SARS-CoV-2 may cause severe, mild, and asymptomatic manifestations of the disease. In this case report, we describe for the first time the clinical symptoms of four patients (three symptomatic; one asymptomatic) from Santiago of Chile, with a complete vaccination schedule with two doses of CoronaVac (Sinovac Life Science) infected with the variant of interest (VOI) B.1.621 (Mu). They were compared with four unvaccinated patients, who had a higher prevalence of symptoms after infection compared to vaccinated patients. In the CoronaVac-vaccinated group, an 80-year-old patient who registered various comorbidities required Invasive mechanical ventilation for 28 days with current home medical recovery discharge. By contrast, in the unvaccinated group, a 71-year-old presented more symptoms with more than 45 days of Invasive mechanical ventilation, which continues to date, presenting greater lung damage than the vaccinated hospitalized patient. This first report evidence differences in the clinical symptomatology of patients vaccinated and non-vaccinated infected with the VOI B.1.621 (Mu) and suggest the protective effects of CoronaVac against this variant., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barrera-Avalos, Luraschi, Acuña-Castillo, Vidal, Mella-Torres, Inostroza-Molina, Vera, Vargas, Hernández, Perez, Vallejos-Vidal, Valdés, Imarai, Reyes-López and Sandino.)
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- 2022
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45. Analysis by real-time PCR of five transport and conservation mediums of nasopharyngeal swab samples to COVID-19 diagnosis in Santiago of Chile.
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Barrera-Avalos C, Luraschi R, Vallejos-Vidal E, Figueroa M, Arenillas E, Barría D, Hernández F, Mateluna C, Mena J, Rioseco C, Torrent C, Vergara C, Gutiérrez G, Quiroz J, Alarcón J, Cartagena J, Cayunao J, Mella-Torres A, Santibañez Á, Tapia S, Undurraga A, Vargas D, Wong V, Inostroza-Molina A, Valdés D, Imarai M, Acuña-Castillo C, Reyes-López FE, and Sandino AM
- Subjects
- COVID-19 Testing, Chile, Culture Media, Humans, Nasopharynx, Pandemics, RNA, RNA, Viral analysis, RNA, Viral genetics, Real-Time Polymerase Chain Reaction, SARS-CoV-2 genetics, Specimen Handling methods, COVID-19 diagnosis
- Abstract
Due to the COVID-19 pandemic, many transport kits have been manufactured to preserve and transport nasopharyngeal swab samples (NPSs) from patients. However, there is no information on the performance of the different virus transport media (VTM) used in COVID-19 diagnosis in the population of Santiago de Chile. We compared the RT-qPCR amplification profile of five different viral transport kit mediums, including DNA/RNA Shield™, NAT, VTM-N, Ezmedlab™, and phosphate-buffered saline (PBS), for NPSs from Central Metropolitan Health Service, Santiago, Chile. The DNA/RNA Shield™ medium showed a better performance in terms of Cq and RFU values for the internal reference RNase P and viral ORF1ab probes. By contrast, the PBS transport medium registered higher Cq values for the viral and reference gene, compared to the other VTM. DNA/RNA Shield™ shows higher relative fluorescence units (RFUs) and lower Cq values for the reference gene. Collectively, our results suggest that the PBS medium could compromise the sample diagnosis because of its lower RT-qPCR performance. The NAT, Ezmedlab and VTM-N, and DNA/RNA Shield™ media show acceptable RT-qPCR parameters and, consequently, seem suitable for use in COVID-19 diagnosis., (© 2021 Wiley Periodicals LLC.)
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- 2022
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46. Tumor-infiltrating exhausted CD8+ T cells dictate reduced survival in premenopausal estrogen receptor-positive breast cancer.
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Egelston CA, Guo W, Tan J, Avalos C, Simons DL, Lim MH, Huang YJ, Nelson MS, Chowdhury A, Schmolze DB, Yim JH, Kruper L, Melstrom L, Margolin K, Mortimer JE, Yuan Y, Waisman JR, and Lee PP
- Subjects
- Biomarkers, Tumor metabolism, CD8-Positive T-Lymphocytes pathology, Disease-Free Survival, Female, Humans, Lymphocytes, Tumor-Infiltrating pathology, Prognosis, Triple Negative Breast Neoplasms immunology, Triple Negative Breast Neoplasms metabolism, Tumor Microenvironment, CD8-Positive T-Lymphocytes immunology, Lymphocytes, Tumor-Infiltrating immunology, Premenopause, Receptors, Estrogen metabolism, Triple Negative Breast Neoplasms pathology
- Abstract
CD8+ tumor-infiltrating lymphocytes (TILs) are associated with improved survival in triple-negative breast cancer (TNBC) yet have no association with survival in estrogen receptor-positive (ER+) BC. The basis for these contrasting findings remains elusive. We identified subsets of BC tumors infiltrated by CD8+ T cells with characteristic features of exhausted T cells (TEX). Tumors with abundant CD8+ TEX exhibited a distinct tumor microenvironment marked by amplified interferon-γ signaling-related pathways and higher programmed death ligand 1 expression. Paradoxically, higher levels of tumor-infiltrating CD8+ TEX associated with decreased overall survival of patients with ER+ BC but not patients with TNBC. Moreover, high tumor expression of a CD8+ TEX signature identified dramatically reduced survival in premenopausal, but not postmenopausal, patients with ER+ BC. Finally, we demonstrated the value of a tumor TEX signature score in identifying high-risk premenopausal ER+ BC patients among those with intermediate Oncotype DX Breast Recurrence Scores. Our data highlight the complex relationship between CD8+ TILs, interferon-γ signaling, and ER status in BC patient survival. This work identifies tumor-infiltrating CD8+ TEX as a key feature of reduced survival outcomes in premenopausal patients with early-stage ER+ BC.
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- 2022
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47. Evaluation of the Immune Response Induced by CoronaVac 28-Day Schedule Vaccination in a Healthy Population Group.
- Author
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Escobar A, Reyes-López FE, Acevedo ML, Alonso-Palomares L, Valiente-Echeverría F, Soto-Rifo R, Portillo H, Gatica J, Flores I, Nova-Lamperti E, Barrera-Avalos C, Bono MR, Vargas L, Simon V, Leiva-Salcedo E, Vial C, Hormazabal J, Cortes LJ, Valdés D, Sandino AM, Imarai M, and Acuña-Castillo C
- Subjects
- Adult, B-Lymphocytes immunology, B-Lymphocytes metabolism, Biomarkers blood, COVID-19 immunology, COVID-19 virology, COVID-19 Vaccines immunology, Chile, Female, Granzymes metabolism, Healthy Volunteers, Humans, Immunity, Cellular drug effects, Immunity, Humoral drug effects, Immunologic Memory drug effects, Interferon-gamma metabolism, Male, Middle Aged, Spike Glycoprotein, Coronavirus immunology, Time Factors, Treatment Outcome, Antibodies, Neutralizing blood, Antibodies, Viral blood, B-Lymphocytes drug effects, COVID-19 prevention & control, COVID-19 Vaccines administration & dosage, Immunization Schedule, Immunogenicity, Vaccine, SARS-CoV-2 immunology
- Abstract
CoronaVac vaccine from Sinovac Life Science is currently being used in several countries. In Chile, the effectiveness of preventing hospitalization is higher than 80% with a vaccination schedule. However, to date, there are no data about immune response induction or specific memory. For this reason, we recruited 15 volunteers without previous suspected/diagnosed COVID-19 and with negative PCR over time to evaluate the immune response to CoronaVac 28 and 90 days after the second immunization (dpi). The CoronaVac administration induces total and neutralizing anti-spike antibodies in all vaccinated volunteers at 28 and 90 dpi. Furthermore, using ELISpot analysis to assay cellular immune responses against SARS-CoV-2 spike protein, we found an increase in IFN-gamma- and Granzyme B-producing cells in vaccinated volunteers at 28 and 90 dpi. Together, our results indicate that CoronaVac induces a robust humoral immune response and cellular immune memory of at least 90 dpi., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Escobar, Reyes-López, Acevedo, Alonso-Palomares, Valiente-Echeverría, Soto-Rifo, Portillo, Gatica, Flores, Nova-Lamperti, Barrera-Avalos, Bono, Vargas, Simon, Leiva-Salcedo, Vial, Hormazabal, Cortes, Valdés, Sandino, Imarai and Acuña-Castillo.)
- Published
- 2022
- Full Text
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48. Systematic Review: microRNAs as Potential Biomarkers in Mild Cognitive Impairment Diagnosis.
- Author
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Ogonowski N, Salcidua S, Leon T, Chamorro-Veloso N, Valls C, Avalos C, Bisquertt A, Rentería ME, Orellana P, and Duran-Aniotz C
- Abstract
The rate of progression from Mild Cognitive Impairment (MCI) to Alzheimer's disease (AD) is estimated at >10% per year, reaching up to 80-90% after 6 years. MCI is considered an indicator of early-stage AD. In this context, the diagnostic screening of MCI is crucial for detecting individuals at high risk of AD before they progress and manifest further severe symptoms. Typically, MCI has been determined using neuropsychological assessment tools such as the Montreal Cognitive Assessment (MoCA) or Mini-Mental Status Examination (MMSE). Unfortunately, other diagnostic methods are not available or are unable to identify MCI in its early stages. Therefore, identifying new biomarkers for MCI diagnosis and prognosis is a significant challenge. In this framework, miRNAs in serum, plasma, and other body fluids have emerged as a promising source of biomarkers for MCI and AD-related cognitive impairments. Interestingly, miRNAs can regulate several signaling pathways via multiple and diverse targets in response to pathophysiological stimuli. This systematic review aims to describe the current state of the art regarding AD-related target genes modulated by differentially expressed miRNAs in peripheral fluids samples in MCI subjects to identify potential miRNA biomarkers in the early stages of AD. We found 30 articles that described five miRNA expression profiles from peripheral fluid in MCI subjects, showing possible candidates for miRNA biomarkers that may be followed up as fluid biomarkers or therapeutic targets of early-stage AD. However, additional research is needed to validate these miRNAs and characterize the precise neuropathological mechanisms., Competing Interests: NC-V, CV, and AB were employed by company Neurognos Spa. The remaining 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. The reviewer EJ-M declared a shared affiliation with one of the authors, TL, to the handling editor at time of review., (Copyright © 2022 Ogonowski, Salcidua, Leon, Chamorro-Veloso, Valls, Avalos, Bisquertt, Rentería, Orellana and Duran-Aniotz.)
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- 2022
- Full Text
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49. The Rapid Antigen Detection Test for SARS-CoV-2 Underestimates the Identification of COVID-19 Positive Cases and Compromises the Diagnosis of the SARS-CoV-2 (K417N/T, E484K, and N501Y) Variants.
- Author
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Barrera-Avalos C, Luraschi R, Vallejos-Vidal E, Mella-Torres A, Hernández F, Figueroa M, Rioseco C, Valdés D, Imarai M, Acuña-Castillo C, Reyes-López FE, and Sandino AM
- Subjects
- COVID-19 Testing, Humans, Pandemics, COVID-19, SARS-CoV-2
- Abstract
Timely detection of severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) by reverse transcription quantitative polymerase chain reaction (RT-qPCR) has been the gold- strategy for identifying positive cases during the current pandemic. However, faster and less expensive methodologies are also applied for the massive diagnosis of COVID-19. In this way, the rapid antigen test (RAT) is widely used. However, it is necessary to evaluate its detection efficiency considering the current pandemic context with the circulation of new viral variants. In this study, we evaluated the sensitivity and specificity of RAT (SD BIOSENSOR, South Korea), widely used for testing and SARS-CoV-2 diagnosis in Santiago of Chile. The RAT showed a 90% (amplification range of 20 ≤ Cq <25) and 10% (amplification range of 25 ≤ Cq <30) of positive SARS-CoV-2 cases identified previously by RT-qPCR. Importantly, a 0% detection was obtained for samples within a Cq value>30. In SARS-CoV-2 variant detection, RAT had a 42.8% detection sensitivity in samples with RT-qPCR amplification range 20 ≤ Cq <25 containing the single nucleotide polymorphisms (SNP) K417N/T, N501Y and E484K, associated with beta or gamma SARS-CoV-2 variants. This study alerts for the special attention that must be paid for the use of RAT at a massive diagnosis level, especially in the current scenario of appearance of several new SARS-CoV-2 variants which could generate false negatives and the compromise of possible viral outbreaks., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barrera-Avalos, Luraschi, Vallejos-Vidal, Mella-Torres, Hernández, Figueroa, Rioseco, Valdés, Imarai, Acuña-Castillo, Reyes-López and Sandino.)
- Published
- 2022
- Full Text
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50. Perceived Stress in Older Dementia Caregivers: Mediation by Loneliness and Depression.
- Author
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Peavy G, Mayo AM, Avalos C, Rodriguez A, Shifflett B, and Edland SD
- Subjects
- Aged, Depression, Humans, Loneliness, Stress, Psychological, Caregivers, Dementia
- Abstract
Coupled with aging, chronic stress experienced by dementia caregivers often leads to deteriorating health. Comparing caregivers and non-caregivers, we tested whether depression and loneliness mediate the relationship between caregiver status and a measure of chronic stress, the Perceived Stress Scale. Seventy-six cognitively normal older adults (mean age 72.7) were identified as caregivers or non-caregivers based on the functional independence of a paired family member. Caregivers reported more perceived stress, depression, and loneliness than non-caregivers. Using multiple mediation analyses, we found that loneliness and depression mediated the relationship of caregiver status with perceived stress. The loneliness effect on perceived stress was both direct and via its relationship with depressive symptoms. The findings suggest loneliness as a likely point of intervention to reduce caregiver stress. Initiatives to enable caregivers to maintain or develop social relationships apart from caregiver responsibilities may mitigate stress and its negative impact on mental and physical health.
- Published
- 2022
- Full Text
- View/download PDF
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