Browsing by Author "Vera, M."

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    Biofilm formation and interspecies interactions in mixed cultures of thermo-acidophilic archaea Acidianus spp. and Sulfolobus metallicus
    (2016) Castro, C.; Zhang, R.; Liu, J.; Bellenberg, S.; Neu, T.; Donati, E.; Sand, W.; Vera, M.
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    High Helicobacter pylori Bacterial Load and Low Cytokine Expression Levels Are Associated with Nodular Gastropathy
    (2020) Mansilla-Vivar, R.; Serrano Honeyman, Carolina; Palma, C.; Vera, M.; Hernandez, C.; Pizarro Rojas, Margarita Alicia; Torres Montes, Paula Javiera; Harris D., Paul R.; Fuentes López, Eduardo; Riquelme Pérez, Arnoldo; Espino Espino, Alberto Antonio; Mansilla-Vivar, R.; Serrano Honeyman, Carolina; Palma, C.; Vera, M.; Hernandez, C.; Pizarro Rojas, Margarita Alicia; Torres, Javiera; Harris D., Paul R.; Fuentes López, Eduardo; Riquelme Pérez, Arnoldo; Espino Espino, Alberto Antonio
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    Impact of Decreasing Respiratory Rate While Tolerating Moderate Hypercapnia on Lung Injury Markers in Patients with Covid-19 Related Acute Respiratory Distress Syndrome
    (2021) Damiani Rebolledo, Luis Felipe; Oviedo Álvarez, Vanessa Andrea; Alegria Aguirre, Luz Katiushka; Basoalto Escobar, Roque Ignacio; Bachmann Barron, María Consuelo; Jalil Contreras, Yorschua Frederick; Bruhn Cruz, Alejandro Rodrigo; Retamal Montes, A.; Santis Fuentes, César Antonio; Vera, M.; Bugedo Tarraza, Guillermo Jaime
    Rationale: Acute respiratory distress syndrome (ARDS) secondary to SARS-CoV-2 pneumonia is associated with a high mortality rate. Protective ventilationstrategies, by decreasing ventilator induced lung injury (VILI), have reduced mortality in patients with ARDS. However, the role of respiratory rate (RR), a centraldeterminant of the energy applied to the lung parenchyma remains uncertain. Objective: To evaluate the role of respiratory rate on systemic pro-inflammatory mediators, as markers of VILI, in patients with Covid-19-associated ARDS (CARDS) Methods: Prospective, randomized crossover trial in patients with CARDS,PaO2:FIO2 ratio less than 200 mmHg, and requiring deep sedation and neuromuscular blockade. All patients were ventilated with a tidal volume of 6 ml/kg IBW,and PEEP and FiO2 according to the ARDSNet table. If PaO2:FIO2 ratio was less than 150 mmHg, patients were positioned in the prone position.Two 12 hoursperiods with a low RR and a high RR, randomly selected, was conducted. Low RR and high RR periods were set to obtain an 8-10 breaths/min difference betweengroups while maintaining pH and PaCO2 within recommended limits. I:E ratio was held constant during the study.Hemodynamic and respiratory mechanics wereregistered, and arterial blood samples drawn for gas exchange and quantification of inflammatory biomarkers at baseline and repeated at 12 and 24 hours. Results: We enrolled 11 patients (10 males, median age 54 [51-66] years, PaO2:FIO2 108 [86-132]), and all of them were in prone position. The low RR (20 [16-23]) vs the high RR (28 [26-32]) was associated with a significantly lower energy applied to the lung (16 [12-19] vs 23 [20-32] J / min, respectively). PaCO2 and pH were kept within the recommended limits (pH 7.30 [7.25-7.35] vs 7.46 [7.43-7.50]; PaCO2 48 (45-63) vs 36 (32-38) mmHg for low and high RR, respectively).There were no significant changes in any of the respiratory mechanics parameters.The change in RR did not induce differences in any inflammatory marker (IL-6,IL-8, TNF-R1) or in the markers of epithelial (receptor for advanced glycation end products, s-RAGE; Surfactant protein D, SP-D), endothelial damage (Angiopoietin2) or the marker of profibrotic activity (transforming growth factor ß, TGF-ß) (table 1). Conclusion: These preliminary results reveal that a decrease in respiratoryrate, tolerating moderate hypercapnia, does not modify the biomarkers of lung damage compared to a strategy of high respiratory rate in patients with CARDS.
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    Is Gamma (P.1) Variant Associated with a Higher Severity in ICU Patients with SARS-CoV-2 Infection
    (2022) Vera, M.; Angulo, J.; Medina, R.; Ferres, M.; Bruhn, A.; Castro, R.; Pardo-Roa, C.
    The Omicron variant of SARS-CoV-2 has been shown to evade neutralizing antibodies elicited by vaccination or infection. Despite the global spread of the Omicron variant, even among highly vaccinated populations, death rates have not increased concomitantly. These data suggest that immune mechanisms beyond antibody-mediated virus neutralization may protect against severe disease. In addition to neutralizing pathogens, antibodies contribute to control and clearance of infections through Fc effector mechanisms. Here, we probed the ability of vaccine-induced antibodies to drive Fc effector activity against the Omicron variant using samples from individuals receiving one of three SARS-CoV-2 vaccines. Despite a substantial loss of IgM, IgA, and IgG binding to the Omicron variant receptor binding domain (RBD) in samples from individuals receiving BNT162b2, mRNA-1273, and CoronaVac vaccines, stable binding was maintained against the full-length Omicron Spike protein. Compromised RBD binding IgG was accompanied by a loss of RBD-specific antibody Fc gamma receptor (Fe gamma R) binding in samples from individuals who received the CoronaVac vaccine, but RBD-specific Fc gamma R2a and Fc gamma R3a binding was preserved in recipients of mRNA vaccines. Conversely, Spike protein-specific antibodies exhibited persistent but reduced binding to Fc gamma Rs across all three vaccines, although higher binding was observed in samples from recipients of mRNA vaccines. This was associated with preservation of Fc gamma R2a and Fc gamma R3a binding antibodies and maintenance of Spike protein-specific antibody-dependent natural killer cell activation. Thus, despite the loss of Omicron neutralization, vaccine-induced Spike protein-specific antibodies continue to drive Fc effector functions, suggesting a capacity for extraneutralizing antibodies to contribute to disease control.
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    Osteoarthritis in Latin America study of demographic and clinical characteristics in 3040 patients
    (2015) Reginato, A.; Riera, H.; Vera, M.; Torres, A.; Espinosa, R.; Esquivel, J.; Felipe, O.; Blas, J.; Rillo, O.; Radrigán Araya, Francisco José Ricardo; Souto, R.; Rossi, C.; Molina, J.; Ballesteros, F.; Papasidero, S.; Guibert, M.
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    PANLAR. Consensus Recommendations for the Management in Osteoarthritis of Hand, Hip, and Knee
    (2016) Rillo, O.; Riera, H.; Acosta, C.; Liendo, V.; Bolanos, J.; Monterola, L.; Nieto, E.; Arape, R.; Franco, L. M.; Radrigán Araya, Francisco José Ricardo; Vera, M.; Papasidero, S.; Espinosa, R.; Esquivel, J. A.; Souto, R.; Rossi, C.; Ballesteros, F.; Vallejo, C.