Browsing by Author "Saavedra, Nicolas"

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    Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus
    (2013) Barrientos, Leticia; Herrera, Christian L.; Montenegro, Gloria; Ortega, Ximena; Veloz, Jorge; Alvear, Marysol; Cuevas, Alejandro; Saavedra, Nicolas; Salazar, Luis A.
    Propolis is a non-toxic natural substance with multiple pharmacological properties including anticancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from the central and southern regions of Chile. The botanical profile was determined by palynological analysis. Total phenolic contents were determined using colorimetric assays. Reverse phase HPLC and HPLC-MS were used to determine the chemical composition. The minimum inhibitory concentration (MIC) was determined on S. mutans and S. sobrinus. All propolis samples were dominated by structures from native plant species. The characterization by HPLC/MS, evidenced the presence of quercetin, myricetin, kaempferol, rutine, pinocembrin, coumaric acid, caffeic acid and caffeic acid phenethyl ester, that have already been described in these propolis with conventional HPLC. Although all propolis samples inhibited the mutans streptococci growth, it was observed a wide spectrum of action (MIC 0.90 to 8.22 mu g mL(-1)). Given that results it becomes increasingly evident the need of standardization procedures, where we combine both the determination of botanical and the chemical characterization of the extracts. Research conducted to date, describes a promising effectiveness of propolis in the prevention of caries and other diseases of the oral cavity, making it necessary to develop studies to identify and understand the therapeutic targets or mechanisms of molecular action of the various compounds present on them.
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    Hybrid Cardiac Rehabilitation Program in a Low-Resource Setting
    (2024) Seron, Pamela; Oliveros, Maria Jose; Marzuca-Nassr, Gabriel Nasri; Morales, Gladys; Roman, Claudia; Munoz, Sergio Raul; Galvez, Manuel; Latin, Gonzalo; Marileo, Tania; Molina, Juan Pablo; Navarro, Rocio; Sepúlveda Varela, Pablo Andrés; Lanas, Fernando; Saavedra, Nicolas; Ulloa, Constanza; Grace, Sherry L.
    IMPORTANCE While effective, cardiovascular rehabilitation (CR) as traditionally delivered is not well implemented in lower-resource settings. OBJECTIVE To test the noninferiority of hybrid CR compared with traditional CR in terms of cardiovascular events. DESIGN, SETTING, AND PARTICIPANTS This pragmatic, multicenter, parallel arm, open-label randomized clinical trial (the Hybrid Cardiac Rehabilitation Trial [HYCARET]) with blinded outcome assessment was conducted at 6 referral centers in Chile. Adults aged 18 years or older who had a cardiovascular event or procedure, no contraindications to exercise, and access to a mobile telephone were eligible and recruited between April 1, 2019, and March 15, 2020, with follow-up until July 29, 2021. INTERVENTIONS Participants were randomized 1:1 in permuted blocks to the experimental arm, which received 10 center-based supervised exercise sessions plus counseling in 4 to 6 weeks and then were supported at home via telephone calls and text messages through weeks 8 to 12, or the control arm, which received the standard CR of 18 to 22 sessions with exercises and education in 8 to 12 weeks. MAIN OUTCOMES AND MEASURES The primary outcome was cardiovascular events or mortality. Secondary outcomes were quality of life, return to work, and lifestyle behaviors measured with validated questionnaires; muscle strength and functional capacity, measured through physical tests; and program adherence and exercise-related adverse events, assessed using checklists. RESULTS A total of 191 participants were included (mean [SD] age, 58.74 [9.80] years; 145 [75.92%] male); 93 were assigned to hybrid CR and 98 to standard CR. At 1 year, events had occurred in 5 unique participants in the hybrid CR group (5.38%) and 9 in the standard CR group (9.18%). In the intention-to-treat analysis, the hybrid CR group had 3.80% (95% CI, -11.13% to 3.52%) fewer cardiovascular events than the standard CR group, and relative risk was 0.59 (95% CI, 0.20-1.68) for the primary outcome. In the per-protocol analysis at different levels of adherence to the intervention, all 95% CIs crossed the noninferiority boundary (eg, 20% adherence: absolute risk difference, - 0.35% [95% CI, -7.56% to 6.85%]; 80% adherence: absolute risk difference, 3.30% [95% CI, - 3.70% to 10.31%]). No between-group differences were found for secondary outcomes except adherence to supervised CR sessions (79.14% [736 of 930 supervised sessions] in the hybrid CR group vs 61.46% [1201 of 1954 sessions] in the standard CR group). CONCLUSIONS AND RELEVANCE The results suggest that a hybrid CR program is noninferior to standard center-based CR in a low-resource setting, primarily in terms of recurrent cardiovascular events and potentially in terms of intermediate outcomes. Hybrid CR may induce superior adherence to supervised exercise. Clinical factors and patient preferences should inform CR model allocation. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT03881150
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    Hybrid cardiac rehabilitation trial (HYCARET): protocol of a randomised, multicentre, non-inferiority trial in South America
    (2019) Seron, Pamela; Oliveros, Maria J.; Marzuca-Nassr, Gabriel N.; Lanas, Fernando; Morales, Gladys; Roman, Claudia; Munoz, Sergio R.; Saavedra, Nicolas; Grace, Sherry L.
    Introduction Cardiac rehabilitation (CR) programmes are well established, and their effectiveness and cost-effectiveness are proven. In spite of this, CR remains underused, especially in lower-resource settings such as Latin America. There is an urgent need to create more accessible CR delivery models to reach all patients in need. This trial aims to evaluate if the prevention of recurrent cardiovascular events is not inferior in a hybrid CR programme compared with a standard programme.