Browsing by Author "Garcia Canete, Patricia Del Carmen"
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- ItemDifferential levels of anti-Mycobacterium tuberculosis-specific IgAs in saliva of household contacts with latent tuberculosis infection(FRONTIERS MEDIA SA, 2023) Ruiz-Tagle Seguel, Cinthya Grace; Naves Pichuante, Rodrigo Antonio; Garcia Canete, Patricia Del Carmen; Guenther, Anna; Schneiderhan-Marra, Nicole; Balcells Marty, Maria ElviraIntroduction: Mucosal immunity is strongly elicited in early stages of many respiratory and enteric infections; however, its role in tuberculosis pathogenesis has been scarcely explored. We aimed to investigate Mycobacterium tuberculosis (Mtb) specific IgA levels in saliva in different stages of latent Tuberculosis Infection (TBI).Methodology: A multiplex bead-based Luminex immunoassay was developed to detect specific IgA against 12 highly immunogenic Mtb antigens. A prospective cohort of household contacts (>14 years) of pulmonary TB cases was established in Santiago, Chile. Contacts were classified as Mtb-infected or not depending on serial interferon-gamma release assay results. Saliva samples were collected and tested at baseline and at a 12-week follow-up.Results: Mtb-specific IgA was detectable at all visits in all participants (n = 168), including the "non-Mtb infected" (n = 64). Significantly higher median levels of IgA were found in the "Mtb infected" compared to the uninfected for anti-lipoarabinomannan (LAM) (110 vs. 84.8 arbitrary units (AU), p < 0.001), anti-PstS1 (117 vs. 83 AU, p < 0.001), anti-Cell Membrane Fraction (CMF) (140 vs. 103 AU, p < 0.001) and anti-Culture Filtrate Proteins (CFP) (median 125 vs. 96 AU, p < 0.001), respectively. Nonetheless, the discriminatory performance of these specific mucosal IgA for TBI diagnosis was low.Conclusion: Saliva holds Mtb-specific IgA against several antigens with increased levels for anti-LAM, anti-PstS1, anti-CMF and anti-CFP found in household contacts with an established TBI. The role of these mucosal antibodies in TB pathogenesis, and their kinetics in different stages of Mtb infection merits further exploring.
- ItemLINC00662 Promotes Aggressive Traits by Modulating OCT4 Expression through miR-335-5p in Gallbladder Cancer Cells(MDPI, 2024) Perez-Moreno, Pablo; Riquelme, Ismael; Bizama Soto, Carolina Del Carmen; Vergara-Gomez, Luis; Tapia, Julio C.; Brebi, Priscilla; Garcia Canete, Patricia Del Carmen; Roa Strauch, Juan Carlos EnriqueLong non-coding RNAs (lncRNAs) are nucleotide sequences that participate in different biological processes and are associated with different pathologies, including cancer. Long intergenic non-protein-coding RNA 662 (LINC00662) has been reported to be involved in different cancers, including colorectal, prostate, and breast cancer. However, its role in gallbladder cancer has not yet been described. In this article, we hypothesize that LINC00662 has an important role in the acquisition of aggressiveness traits such as a stem-like phenotype, invasion, and chemoresistance in gallbladder cancer. Here, we show that LINC00662 is associated with larger tumor size and lymph node metastasis in patients with gallbladder cancer. Furthermore, we show that the overexpression of LINC00662 promotes an increase in CD133+/CD44+ cell populations and the expression of stemness-associated genes. LINC00662 promotes greater invasive capacity and the expression of genes associated with epithelial-mesenchymal transition. In addition, the expression of LINC00662 promotes resistance to cisplatin and 5-fluorouracil, associated with increased expression of chemoresistance-related ATP-binding cassette (ABC) transporters in gallbladder cancer (GBC) cell lines. Finally, we show that the mechanism by which LINC00662 exerts its function is through a decrease in microRNA 335-5p (miR-335-5p) and an increase in octamer-binding transcription factor 4 (OCT4) in GBC cells. Thus, our data allow us to propose LINC00662 as a biomarker of poor prognosis and a potential therapeutic target for patients with GBC.
- ItemPresence of Bartonella henselae in cats, in Chile(Sociedad Medica de Santiago, 2005) Ferres Garrido, Marcela Viviana; Abarca Villaseca, Katia; Godoy M., Paula; Chanqueo C., Leonardo; Garcia Canete, Patricia Del Carmen; Palavecino, Elizabeth; Vial C., Pablo A.; Gabriela Méndez R.; Valdés O., Alicia; Ernst M., Santiago; Thibaut L., Julio; Koberg J.The availability of a serologic test for cat scratch disease in humans has allowed the diagnosis of an increasing number of cases of this disease in Chile. Aim: To perform a serological survey for Bartonella henselae among cats in Chile. Material and methods: Blood samples from 187 cats living in three Chilean cities were obtained. IgG antibodies againts Bartonella henselae were measured using indirect immunofluorescence. Blood cultures were done in 60 samples. The presence of Bartonella henselae in positive cultures was confirmed by restriction fragment length polymorphism polimerase chain reaction (RFLP-PCR). Results: The general prevalence of IgG antibodies against Bartonella henselae was 85.6%. No differences in this prevalence were found among cats younger or older than 1 year, or those infested or not infested with fleas. However domestic cats had a lower prevalence when compared with stray cats (73 and 90% respectively, p <0.01). Bartonella henselae was isolated in 41%of blood cultures. All the isolated were confirmed as Bartonella henselae by KFLP-PCR Conclusions: This study found an important reservoir of Bartonella henselae in Chilean cats and therefore a high risk of exposure in humans who have contact with them (Rev Méd Chile 2005; 133:1465-71).
- ItemPrimera comunicación en Chile de la detección del gen mcr-1 en un aislado clínico(Sociedad Chilena de Infectologia, 2018) Legarraga Raddatz, Paulette; Wozniak Banchero, Aniela; Garcia Canete, Patricia Del Carmen; Prado Stuardo, Sandra Antonia; Estrella Cedeno, Laura Estefania© 2018, Sociedad Chilena de Infectologia. All rights reserved.Recently it was described the plasmidial gene mcr-1 associated with colistin resistance. We screened by PCR and sequencing for gene mcr-1 in thirteen clinical isolates resistant to colistin. We observed amplification in one E. coli. To our knowledge, this is the first report of the presence of mcr-1 gene in Chile.
- ItemReduced microbial diversity of the nasopharyngeal microbiome in household contacts with latent tuberculosis infection(NATURE PORTFOLIO, 2023) Ruiz-Tagle Seguel, Cinthya Grace; Ugalde, Juan A.; Naves Pichuante, Rodrigo Antonio; Araos, Rafael; Garcia Canete, Patricia Del Carmen; Balcells Marty, Maria ElviraThe upper respiratory tract is an obliged pathway for respiratory pathogens and a healthy microbiota may support the host's mucosal immunity preventing infection. We analyzed the nasopharyngeal microbiome in tuberculosis household contacts (HHCs) and its association with latent tuberculosis infection (TBI). A prospective cohort of HHCs was established and latent TBI status was assessed by serial interferon-& gamma; release assay (IGRA). Nasopharyngeal swabs collected at baseline were processed for 16S rRNA gene sequencing. The 82 participants included in the analysis were classified as: (a) non-TBI [IGRA negative at baseline and follow-up, no active TB (n = 31)], (b) pre-TBI [IGRA negative at baseline but converted to IGRA positive or developed active TB at follow-up (n = 16)], and (c) TBI [IGRA positive at enrollment (n = 35)]. Predominant phyla were Actinobacteriota, Proteobacteria, Firmicutes and Bacteroidota. TBI group had a lower alpha diversity compared to non-TBI (p(adj) = 0.04) and pre-TBI (p(adj) = 0.04). Only TBI and non-TBI had beta diversity differences (p(adj) = 0.035). Core microbiomes' had unique genera, and genus showed differential abundance among groups. HHCs with established latent TBI showed reduced nasopharyngeal microbial diversity with distinctive taxonomical composition. Whether a pre-existing microbiome feature favors, are a consequence, or protects against Mycobacterium tuberculosis needs further investigation.
- ItemUna regla de predicción clínica ¿anticipa el diagnóstico de la faringitis estreptocóccica en niños de 2 a 15 años?(SOC CHILENA INFECTOLOGIA, 2018) Karzulovic Busch, Lorena Karina; Garcia Canete, Patricia Del Carmen; Wozniak Banchero, Aniela; Villarroel Del Pino, Luis Antonio; Hirsch Birn, Tamara Regina; Concha Murray, Ida Angelica; Catalan, Mora Silvia; Cifuentes Águila, Lorena IsabelBackground: The etiology of a streptococcal pharyngitis must be documented by laboratory techniques to avoid unnecessary antimicrobial treatment, but this strategy increases cost for the patient. Available scores applied in children or adults are imperfect. Aim: To develop a clinical prediction rule to aid the diagnostic process of streptococcal pharyngitis (SP) in children in a low-resource setting. Methods: Three hundred and eighteen patients aged 2 to 15 years who were evaluated for suspected SP at the Pediatric Emergency Department and the Pediatric Ambulatory Unit of Red Salud UC-Christus entered the study. A throat culture and a rapid antigen detection test for Streptococcus pyogenes were obtained from each patient. Data were analyzed for possible clinical predictors of SP with univariate and multiple regression analyses. Results: Seventy-three cases of SP were diagnosed (23.9%). In the univariate analysis, fever was inversely associated with SP (p = 0.002). Odynophagia, palatal petechiae, and season of the year (autumn and winter) were positively associated with SP (p = 0.007, p < 0.001 and p = 0.03 respectively). In multiple regression analysis the models did not have sufficient power to predict streptococcal etiology. Conclusion: Clinical predictors, even those systematically included in clinical prediction rules, did not show sufficient predictive power to safely include or exclude SP in this setting, and thus, it is necessary to improve access to confirmatory tests.