Browsing by Author "Gonzalez, Marcela"

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    A Role for the Insular Cortex in Long-Term Memory for Context-Evoked Drug Craving in Rats
    (2012) Contreras, Marco; Billeke, Pablo; Vicencio, Sergio; Madrid, Carlos; Perdomo, Gueton; Gonzalez, Marcela; Torrealba, Fernando
    Drug craving critically depends on the function of the interoceptive insular cortex, and may be triggered by contextual cues. However, the role of the insula in the long-term memory linking context with drug craving remains unknown. Such a memory trace probably resides in some neocortical region, much like other declarative memories. Studies in humans and rats suggest that the insula may include such a region. Rats chronically implanted with bilateral injection cannulae into the high-order rostral agranular insular cortex (RAIC) or the primary interoceptive posterior insula (pIC) were conditioned to prefer the initially aversive compartment of a 2-compartment place preference apparatus by repeatedly pairing it to amphetamine. We found a reversible but long-lasting loss (ca. 24 days) of amphetamine-conditioned place preference (CPP) and a decreased expression in the insula of zif268, a crucial protein in memory reconsolidation, when anisomycin (ANI) was microinjected into the RAIC immediately after the reactivation of the conditioned amphetamine/context memory. ANI infusion into the RAIC without reactivation did not change CPP, whereas ANI infusion into pIC plus caused a 15 days loss of CPP. We also found a 24 days loss of CPP when we reversibly inactivated pIC during extinction trials. We interpret these findings as evidence that the insular cortex, including the RAIC, is involved in a context/drug effect association. These results add a drug-related memory function to the insular cortex to the previously found role of the pIC in the perception of craving or malaise. Neuropsychopharmacology (2012) 37, 2101-2108; doi:10.1038/npp.2012.59; published online 25 April 2012
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    Clinical Efficacy of SARS-CoV-2 Vaccination in Hemodialysis Patients
    (2022) Torres, Ruben; Toro, Luis; Eugenia Sanhueza, Maria; Lorca, Eduardo; Ortiz, Mireya; Pefaur, Jacqueline; Clavero, Rene; Machuca, Eduardo; Gonzalez, Fernando; Herrera, Patricia; Mocarquer, Alfredo; Frias, Alondra; Roessler, Eric; Munoz, Carolina; Nunez, Miguel; Aravena, Cesar; Quintana, Enrique; Lemus, Juan; Lillo, Mario; Reynolds, Enrique; Morales, Alvaro; Pais, Edgard; Fiabane, Andrea; Parra-Lucares, Alfredo; Garrido, Cristian; Mendez-Valdes, Gabriel; Villa, Eduardo; Mansilla, Rodrigo; Sotomayor, Germana; Gonzalez, Marcela; Miranda, Cecilia; Briones, Eduardo; Gomez, Esteban; Mezzano, Sergio; Bernales, Waldo; Rocca, Ximena; Espinoza, Oscar; Zuniga, Eric; Aragon, Henry; Badilla, Marta; Valenzuela, Marcela; Escobar, Luis; Zamora, Daniela; Flores, Ivan; Tapia, Beatriz; Borquez, Tamara; Herrera, Patricio
    Introduction: The COVID-19 pandemic is a global public health problem. Patients with end-stage renal disease on hemodialysis are at a higher risk of infection and mortality than the general population. Worldwide, a vaccination campaign has been developed that has been shown to reduce severe infections and deaths in the general population. However, there are currently limited data on the clinical efficacy of vaccinations in the hemodialysis population.
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    Immunolocalization of kappa opioid receptors in the axon initial segment of a group of embryonic mesencephalic dopamine neurons
    (2022) Pilar Escobar, Angelica; Meza, Rodrigo C.; Gonzalez, Marcela; Henny, Pablo; Andres, Maria Estela
    The dopamine mesolimbic system is a major circuit involved in controlling goal-directed behaviors. Dopamine D2 receptors (D2R) and kappa opioid receptors (KOR) are abundant Gi protein-coupled receptors in the mesolimbic system. D2R and KOR share several functions in dopamine mesencephalic neurons, such as regulation of dopamine release and uptake, and firing of dopamine neurons. In addition, KOR and D2R modulate each other functioning. This evidence indicates that both receptors functionally interact, however, their colocalization in the mesostriatal system has not been addressed. Immunofluorescent assays were performed in cultured dopamine neurons and adult mice's brain tissue to answer this question. We observed that KOR and D2R are present in similar density in dendrites and soma of cultured dopamine neurons, but in a segregated manner. Interestingly, KOR immunolabelling was observed in the first part of the axon, colocalizing with Ankyrin in 20% of cultured dopamine neurons, indicative that KOR is present in the axon initial segment (AIS) of a group of dopaminergic neurons. In the adult brain, KOR and D2R are also segregated in striatal tissue. While the KOR label is in fiber tracts such as the striatal streaks, corpus callosum, and anterior commissure, D2R is located mainly within the striatum and nucleus accumbens, surrounding fiber tracts. D2R is also localized in some fibers that are mostly different from those positives for KOR. In conclusion, KOR and D2R are present in the soma and dendrites of mesencephalic dopaminergic neurons, but KOR is also found in the AIS of a subpopulation of these neurons.
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    Oral polio vaccine in infants does not interfere in detection of enterovirus in blood
    (SOC CHILENA INFECTOLOGIA, 2013) Gonzalez, Marcela; Sandoval, Carmen; Valenzuela, Patricia; Montecinos, Luisa; Martinez, Constanza; Godoy, Paula; Abarca, Katia
    Introduction: There is not known if a viraemia post-oral polio vaccine (OPV) is detectable by modern molecular techniques. Such viraemia could affect the performance of the real time-polymerase chain reaction (PCR) for non polio enterovirus (EV) detection, technique of growing clinical use for the study of febrile infants. Objective: To determine viraemia post-first dose of OPV in healthy infants, by molecular techniques. Patients and Methods: 50 infants less than three months without previous VPO were randomized in 5 groups: a control group with prevaccination blood sample (BS), group 1 BS at day 2, group 2 BS at day 4, group 3, BS at day 6 and group 4, BS at day 8 post-vaccination. Conventional and specific PCR for poliovirus and real time PCR for non polio EV were performed in BS and in OPV samples. Results: No genetic material of poliovirus was detected in any infant, while in 9 of them (18%) non polio EV was identified. Real time PCR for EV did not amplify poliovirus from OPV samples. Discussion: Results suggest that no post VPO viraemia detectable by molecular methods exists. Considering that real time PCR for EV does not allow to identify polio virus, no false positives of the test are expected as a result of a recent VPO vaccination. We documented presence of non polio EV in blood of healthy asymptomatic infants.
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    Safety and Non-Inferiority Evaluation of Two Immunization Schedules with an Inactivated SARS-CoV-2 Vaccine in Adults: A Randomized Clinical Trial
    Abarca Villaseca, Katia; Iturriaga Ortiz, Carolina Alejandra; Urzua, Marcela; Le Corre Perez, Monique Nicole; Pineda Núñez, Augusto Naim; Fernandez Anwandter, Carolina; Domínguez De Landa, María Angelica; González Carbonell, Pablo Andrés; Bueno, Susan M.; Donato, Paulina; Espinoza, Pilar; Fuentes, Daniela; Gonzalez, Marcela; Guzman, Paula; Munoz-Venturelli, Paula; Perez, Carlos M.; Potin, Marcela; Rojas, Alvaro; Gonzalez-Aramundiz, Jose, V; Galvez, Nicolas M. S.; Aguirre-Boza, Francisca; Aljaro, Sofia; Federico Batiz, Luis; Campisto, Yessica; Cepeda, Mariela; Cortes, Aaron; Lopez, Sofia; Loreto Perez, Maria; Schilling, Andrea; Kalergis, Alexis M.
    Several vaccines have been developed to control the COVID-19 pandemic. CoronaVac (R), an inactivated SARS-CoV-2 vaccine, has demonstrated safety and immunogenicity, preventing severe COVID-19 cases. We investigate the safety and non-inferiority of two immunization schedules of CoronaVac (R) in a non-inferiority trial in healthy adults. A total of 2302 healthy adults were enrolled at 8 centers in Chile and randomly assigned to two vaccination schedules, receiving two doses with either 14 or 28 days between each. The primary safety and efficacy endpoints were solicited adverse events (AEs) within 7 days of each dose, and comparing the number of cases of SARS-CoV-2 infection 14 days after the second dose between the schedules, respectively. The most frequent local AE was pain at the injection site, which was less frequent in participants aged >= 60 years. Other local AEs were reported in less than 5% of participants. The most frequent systemic AEs were headache, fatigue, and myalgia. Most AEs were mild and transient. There were no significant differences for local and systemic AEs between schedules. A total of 58 COVID-19 cases were confirmed, and all but 2 of them were mild. No differences were observed in the proportion of COVID-19 cases between schedules. CoronaVac (R) is safe, especially in >= 60-year-old participants. Both schedules protected against COVID-19 hospitalization.