Browsing by Author "Padilla, Oslando"

Now showing 1 - 20 of 33
  • Thumbnail Image
    Item
    11 beta-hydroxysteroid dehydrogenase type-2 and type-1 (11 beta-HSD2 and 11 beta-HSD1) and 5 beta-reductase activities in the pathogenia of essential hypertension
    (HUMANA PRESS INC, 2010) Campino, Carmen; Carvajal, Cristian A.; Cornejo, Javiera; San Martin, Betty; Olivieri, Oliviero; Guidi, Giancesare; Faccini, Giovanni; Pasini, Francesco; Sateler, Javiera; Baudrand, Rene; Mosso, Lorena; Owen, Gareth I.; Kalergis, Alexis M.; Padilla, Oslando; Fardella, Carlos E.
    Cortisol availability is modulated by several enzymes: 11 beta-HSD2, which transforms cortisol (F) to cortisone (E) and 11 beta-HSD1 which predominantly converts inactive E to active F. Additionally, the A-ring reductases (5 alpha- and 5 beta-reductase) inactivate cortisol (together with 3 alpha-HSD) to tetrahydrometabolites: 5 alpha THF, 5 beta THF, and THE. The aim was to assess 11 beta-HSD2, 11 beta-HSD1, and 5 beta-reductase activity in hypertensive patients. Free urinary F, E, THF, and THE were measured by HPLC-MS/MS in 102 essential hypertensive patients and 18 normotensive controls. 11 beta-HSD2 enzyme activity was estimated by the F/E ratio, the activity of 11 beta-HSD1 in compare to 11 beta-HSD2 was inferred by the (5 alpha THF + 5 beta THF)/THE ratio and 5 beta-reductase activity assessed using the E/THE ratio. Activity was considered altered when respective ratios exceeded the maximum value observed in the normotensive controls. A 15.7% of patients presented high F/E ratio suggesting a deficit of 11 beta-HSD2 activity. Of the remaining 86 hypertensive patients, two possessed high (5 alpha THF + 5 beta THF)/THE ratios and 12.8% had high E/THE ratios. We observed a high percentage of alterations in cortisol metabolism at pre-receptor level in hypertensive patients, previously misclassified as essential. 11 beta-HSD2 and 5 beta-reductase decreased activity and imbalance of 11 beta-HSDs should be considered in the future management of hypertensive patients.
  • No Thumbnail Available
    Item
    11β-hydroxysteroid dehydrogenase type 2 polymorphisms and activity in a Chilean essential hypertensive and normotensive cohort.
    (2012) Campino, Carmen; Quinteros, Hector; Owen, Gareth I.; Carvajal, Cristian A.; Morales, Mauricio; Olivieri, Oliviero; Guidi, Giancesare; Faccini, Giovanni; Pasini, Francesco; Baudrand, Rene; Padilla, Oslando; Valdivia, Carolina; Thichauer, Juan; Lagos, Carlos F.; Kalergis, Alexis M.; Fardella, Carlos E.
    BACKGROUND: 11β-hydroxysteroid dehydrogenase type 2 enzyme (11β-HSD2) inactivates cortisol (F) to cortisone (E); its impairment is associated with hypertension. We reported that 15.7% of the Chilean essential hypertensives possessed a high F/E ratio suggesting a partial deficit in 11β-HSD2 activity. It has been reported that the G534A(Glu178/Glu) polymorphism in the HSD11B2 gene is associated with hypertension. Investigate the frequency of the G534A polymorphism and its correlation with the glucocorticoid profile in Chilean essential hypertensive and normotensive subjects. METHODS: Essential hypertensive outpatients (n = 232) and normotensive subjects (n = 74) were recruited. A change in the AluI restriction enzyme digest pattern, caused by the presence of the G534A polymorphism, was utilized to screen DNA isolated from leukocytes within the cohort before confirmation by sequencing. Plasma renin activity (PRA), serum aldosterone, F, and E were measured by radioimmunoassay. Urinary tetrahydrocortisol (THF), 5α-tetrahydrocortisol (5α-THF), and tetrahydrocortisone (THE) were measured by gas chromatography-mass spectrometry. RESULTS: G534A polymorphism frequency was similar between hypertensive patients (19 of 232; 8.2%) and normotensive subjects (7 of 74; 9.5%). When categorized by presence or absence of the G534A polymorphism, no significant differences in the serum F/E ratio or other measured biochemical variables were detected. Despite a previous report that the G534A polymorphism is associated with a neighboring C468A (Thr156/Thr) polymorphism, analysis within our cohort showed that only one patient in each group presented with this double polymorphism. CONCLUSIONS: We report the frequency of the G534A polymorphism in the Spanish-Amerindian population. No correlation was detected between this polymorphism and the presence of hypertension and biochemical parameters in this Chilean cohort.
  • No Thumbnail Available
    Item
    A Bayesian Mixture Cure Rate Model for Estimating Short-Term and Long-Term Recidivism
    (2023) de la Cruz, Rolando; Fuentes, Claudio; Padilla, Oslando
    Mixture cure rate models have been developed to analyze failure time data where a proportion never fails. For such data, standard survival models are usually not appropriate because they do not account for the possibility of non-failure. In this context, mixture cure rate models assume that the studied population is a mixture of susceptible subjects who may experience the event of interest and non-susceptible subjects that will never experience it. More specifically, mixture cure rate models are a class of survival time models in which the probability of an eventual failure is less than one and both the probability of eventual failure and the timing of failure depend (separately) on certain individual characteristics. In this paper, we propose a Bayesian approach to estimate parametric mixture cure rate models with covariates. The probability of eventual failure is estimated using a binary regression model, and the timing of failure is determined using a Weibull distribution. Inference for these models is attained using Markov Chain Monte Carlo methods under the proposed Bayesian framework. Finally, we illustrate the method using data on the return-to-prison time for a sample of prison releases of men convicted of sexual crimes against women in England and Wales and we use mixture cure rate models to investigate the risk factors for long-term and short-term survival of recidivism.
  • Thumbnail Image
    Item
    Administration of angiotensin II and a bradykinin B2 receptor blocker in midpregnancy impairs gestational outcome in guinea pigs
    (2014) Valdés Stromilli, Gloria; Schneider, Daniela; Corthorn H., Jenny; Ortíz, Rita; Acuña, Stephanie; Padilla, Oslando
    Abstract Background The opposing renin-angiotensin system (RAS) and kallikrein-kinin system (KKS) are upregulated in pregnancy and localize in the utero-placental unit. To test their participation as counter-regulators, circulating angiotensin II (AII) was exogenously elevated and the bradykinin B2 receptor (B2R) was antagonized in pregnant guinea-pigs. We hypothesized that disrupting the RAS/KKS balance during the period of maximal trophoblast invasion and placental development would provoke increased blood pressure, defective trophoblast invasion and a preeclampsia-like syndrome. Methods Pregnant guinea-pigs received subcutaneous infusions of AII (200 μg/kg/day), the B2R antagonist Bradyzide (BDZ; 62.5 microg/kg/day), or both (AII + BDZ) from gestational day 20 to 34. Non-pregnant cycling animals were included in a control group (C NP) or received AII + BDZ (AII + BDZ NP) during 14 days. Systolic blood pressure was determined during cycle in C NP, and on the last day of infusion, and 6 and 26 days thereafter in the remaining groups. Twenty six days after the infusions blood and urine were extracted, fetuses, placentas and kidneys were weighed, and trophoblast invasion of spiral arteries was defined in the utero-placental units by immunocytochemistry. Results Systolic blood pressure transiently rose in a subgroup of the pregnant females while receiving AII + BDZ infusion, but not in AII + BDZ NP. Plasma creatinine was higher in AII- and BDZ-treated dams, but no proteinuria or hyperuricemia were observed. Kidney weight increased in AII + BDZ-treated pregnant and non-pregnant females. Aborted and dead fetuses were increased in dams that received AII and AII + BDZ. The fetal/placental weight ratio was reduced in litters of AII + BDZ-treated mothers. All groups that received interventions during pregnancy showed reduced replacement of endothelial cells by extravillous trophoblasts in lateral and myometrial spiral arteries. Conclusions The acute effects on fetal viability, and the persistently impaired renal/placental sufficiency and incomplete arterial remodeling implicate the RAS and KKS in the adaptations in pregnancy. The results partially confirm our hypothesis, as a preeclampsia-like syndrome was not induced. We demonstrate the feasibility of characterizing systemic and local modifications in pregnant guinea-pig, supporting its use to study normal placentation and related disorders.Abstract Background The opposing renin-angiotensin system (RAS) and kallikrein-kinin system (KKS) are upregulated in pregnancy and localize in the utero-placental unit. To test their participation as counter-regulators, circulating angiotensin II (AII) was exogenously elevated and the bradykinin B2 receptor (B2R) was antagonized in pregnant guinea-pigs. We hypothesized that disrupting the RAS/KKS balance during the period of maximal trophoblast invasion and placental development would provoke increased blood pressure, defective trophoblast invasion and a preeclampsia-like syndrome. Methods Pregnant guinea-pigs received subcutaneous infusions of AII (200 μg/kg/day), the B2R antagonist Bradyzide (BDZ; 62.5 microg/kg/day), or both (AII + BDZ) from gestational day 20 to 34. Non-pregnant cycling animals were included in a control group (C NP) or received AII + BDZ (AII + BDZ NP) during 14 days. Systolic blood pressure was determined during cycle in C NP, and on the last day of infusion, and 6 and 26 days thereafter in the remaining groups. Twenty six days after the infusions blood and urine were extracted, fetuses, placentas and kidneys were weighed, and trophoblast invasion of spiral arteries was defined in the utero-placental units by immunocytochemistry. Results Systolic blood pressure transiently rose in a subgroup of the pregnant females while receiving AII + BDZ infusion, but not in AII + BDZ NP. Plasma creatinine was higher in AII- and BDZ-treated dams, but no proteinuria or hyperuricemia were observed. Kidney weight increased in AII + BDZ-treated pregnant and non-pregnant females. Aborted and dead fetuses were increased in dams that received AII and AII + BDZ. The fetal/placental weight ratio was reduced in litters of AII + BDZ-treated mothers. All groups that received interventions during pregnancy showed reduced replacement of endothelial cells by extravillous trophoblasts in lateral and myometrial spiral arteries. Conclusions The acute effects on fetal viability, and the persistently impaired renal/placental sufficiency and incomplete arterial remodeling implicate the RAS and KKS in the adaptations in pregnancy. The results partially confirm our hypothesis, as a preeclampsia-like syndrome was not induced. We demonstrate the feasibility of characterizing systemic and local modifications in pregnant guinea-pig, supporting its use to study normal placentation and related disorders.
  • Thumbnail Image
    Item
    Análisis psicométrico del cuestionario DREEM para medir el ambiente de aprendizaje en Chile.
    (2015) Herrera R., Cristian; Padilla, Oslando; Solís, Nancy; Pizarro Rojas, Margarita Alicia; Kattan Tala, Eduardo José; Díaz P., Luis Antonio; Riquelme Pérez, Arnoldo
  • No Thumbnail Available
    Item
    Association of adenotonsillectomy with wheezing episodes in childhood: A secondary analysis of the Childhood Adenotonsillectomy Trial
    (2023) Castro-Rodriguez, Jose A.; Biancardi, Fiorella; Padilla, Oslando; Beckhaus, Andrea A.; Tapia, Ignacio E.
    BackgroundObservational studies suggest that asthma/wheezing improves after adenotonsillectomy (AT). However, there is a paucity of randomized clinical trial (RCT) specifically studying the effects of AT in asthma/wheezing. Therefore, we conducted a post-hoc analysis of the Childhood Adenotonsillectomy Trial (CHAT), the largest RCT of AT in children with obstructive sleep apnea (OSA) to test the hypothesis that AT would result in fewer wheezing episodes. MethodsIn the CHAT study, 464 children with OSA, aged 5-9 years, were randomized to early AT (n = 226) or watchful waiting with supportive care (WWSC) (n = 227). For this post-hoc analysis, children were categorized as having "any wheezing" versus "no wheezing" at baseline and at 7 months of follow-up. A multivariate analysis was conducted to evaluate the association between "any wheezing" at follow-up and treatment group after controlling for several potential confounders. ResultsChildren in the "any wheezing" group were predominantly black, had more allergic rhinitis, eczema, second-hand smoke exposure, body mass index, apnea-hypopnea index (AHI), and had lower maternal education and family income than those in the "no wheezing group." In the AT arm, the prevalence of wheezing significantly decreased from baseline to follow-up (at 7 months of the intervention) (47% vs. 21.6%, p < 0.001); while in the WWSC arms did not change (45.2% vs. 43.1%, p = 0.67). In the multivariate analysis, second-hand smoke exposure, wheezing at baseline, and belong to WWSC arm (odds ratio: 3.65 [2.16-6.19]) increase the risk of wheezing at follow-up. ConclusionThis study demonstrated that AT decreased the risk of wheezing at 7 months of follow-up.
  • Thumbnail Image
    Item
    Association of Remote Hypertension in Pregnancy With Coronary Artery Disease A Case-Control Study
    (LIPPINCOTT WILLIAMS & WILKINS, 2009) Valdes, Gloria; Quezada, Felipe; Marchant, Eugenio; von Schultzendorff, Astrid; Moran, Sergio; Padilla, Oslando; Martinez, Alejandro
    Because hypertensive pregnancies have been associated with increased cardiovascular disease, we aimed to identify whether angiographically characterized coronary artery disease differed in women with previous normotensive pregnancies or hypertensive pregnancies (HPs). The study group included 217 parous women, aged 60.9 +/- 9.2 (SD) years, who required coronary angiography between January 2006 and December 2007, 36.8 +/- 9.9 and 28.8 +/- 10.5 years after their first and last pregnancy, respectively; 146 had normotensive pregnancies and 71 had >= 1 HP, according to a questionnaire including reproductive history and cardiovascular risks. Body mass index, smoking, and frequency of diabetes were similar in both groups. Chronic hypertension (93% versus 78%; P=0.007), hyperlipidemia (82% versus 69%; P=0.049), and premature familial cardiovascular disease (42% versus 20%; P=0.001) prevailed in HPs. Participants with HPs were younger (58.9 +/- 8.3 versus 61.9 +/- 9.6 years; P=0.025) than participants with normotensive pregnancies. Although 49% of all participants had hemodynamically significant coronary artery disease (>= 70% stenosis), no differences were observed between groups in the number of stenotic arteries; however, their number increased by 28% and 22% over a 10-year period in HPs and normotensive pregnancies, respectively (P=0.034). Multivariate analysis showed that HPs had a nonsignificant risk of having coronary artery disease (odds ratio: 1.21; 95% CI: 0.64 to 2.28), and being a current smoker (odds ratio: 4.13; 95% CI: 1.85 to 9.25), a diabetic (odds ratio: 2.29; 95% CI: 1.85 to 9.25), or having a family history of premature cardiovascular disease (odds ratio: 2.34; 95% CI: 1.17 to 2.39) significantly increased the risk of coronary artery disease. This study demonstrates that women with HPs have earlier coronary disease, probably related to intermediate cardiovascular risks that have a gestational expression. (Hypertension. 2009; 53: 733-738.)
  • Thumbnail Image
    Item
    Benefit of adjuvant 5-fluorouracil based chemotherapy for colon cancer: a retrospective cohort study
    (SOC MEDICA SANTIAGO, 2016) Mondaca, Sebastian; Villalon, Constanza; Luis Leal, Jose; Zuniga, Alvaro; Bellolio, Felipe; Padilla, Oslando; Palma, Silvia; Garrido, Marcelo; Nervi, Bruno
    Background: Multiple clinical trials have demonstrated the benefits of adjuvant 5-fluorouracil-based chemotherapy for patients with resectable colon cancer (CC), especially in stage III. Aim: To describe the clinical characteristics of a cohort of CC patients treated at a single university hospital in Chile since 2002, and to investigate if chemotherapy had an effect on survival rates. Material and Methods: Review of a tumor registry of the hospital. Medical records of patients with CC treated between 2002 and 2012 were reviewed. Death certificates from the National Identification Service were used to determine mortality. Overall survival was described using the Kaplan-Meier method. A multivariate Cox proportional hazard regression model was also used. Results: A total of 370 patients were treated during the study period (202 in stage II and 168 in stage III). Adjuvant chemotherapy was administered to 22 and 70% of patients in stage II and III respectively. The median follow-up period was 4.6 years. The 5-year survival rate for stage II patients was 79% and there was no benefit observed with adjuvant chemotherapy. For stage III patients, the 5-year survival rate was 81% for patients who received adjuvant chemotherapy, compared to 56% for those who did not receive chemotherapy (hazard ratio (HR): 0.29; 95% confidence interval (CI): 0.15-0.56). The benefit of chemotherapy was found to persist after adjustment for other prognostic variables (HR: 0.47; 95% CI: 0.23-0.94). Conclusions: Patients with colon cancer in stage III who received adjuvant chemotherapy had a better overall survival.
  • No Thumbnail Available
    Item
    Bradykinin Exerts Independent Effects on Trophoblast Invasion and Blood Pressure in Pregnant Guinea Pigs
    (2020) Valdes, Gloria; Acuna, Stephanie; Schneider, Daniela; Ortiz, Rita; Padilla, Oslando
    Introduction: The pleiotropic kininogen-kallikrein-kinin system is upregulated in pregnancy and localizes in the uteroplacental unit. To identify the systemic and local participation of the bradykinin type 2 receptor (B2R), this was antagonized by Bradyzide (BDZ) during 2 periods: from days 20 to 34 and from days 20 to 60 in pregnant guinea pigs. Methods: Pregnant guinea pigs received subcutaneous infusions of saline or BDZ from gestational day 20 until sacrifice on day 34 (Short B2R Antagonism [SH-B2RA]) or on day 60 (Prolonged B2R Antagonism [PR-B2RA]). In SH-BDZA, systolic blood pressure was determined on day 34, while in PR-BDZA it was measured preconceptionally, at days 40 and 60. On gestational day 60, plasma creatinine, uricemia, proteinuria, fetal, placental and maternal kidney weight, and the extent of trophoblast invasion were evaluated. Results: The SH-B2RA increased systolic blood pressure on day 34 and reduced trophoblast myometrial invasion, spiral artery remodeling, and placental sufficiency. The PR-B2RA suppressed the normal blood pressure fall observed on days 40 and 60; vascular transformation, placental efficiency, urinary protein, serum creatinine, and uric acid did not differ between the groups. The proportion of all studied mothers with lost fetuses was greater under BDZ infusion than in controls. Conclusion: The increased systolic blood pressure and transient reduction in trophoblast invasion and fetal/placental weight in the SH-B2R blockade and the isolated impact on blood pressure in the PR-B2R blockade indicate that bradykinin independently modulates systemic hemodynamics and the uteroplacental unit through cognate vascular and local B2R receptors.
  • Thumbnail Image
    Item
    CEACLIN, an instrument suited to identify medical students' strategies to learn in pre-clerkship years
    (SOC MEDICA SANTIAGO, 2015) Bitran, Marcela; Padilla, Oslando; Zuniga, Denisse; Leiva, Isabel; Calderon, Maribel; Riquelme, Arnoldo
    Background: Upon the beginning of pre-clerkship years, medical students must develop strategies to learn from experience and to improve their relational skills to communicate with patients. Aim: To develop an instrument to identify the strategies used by medical students to learn in clinical contexts. Material and Methods: Using a Delfi technique to reach consensus, a national panel of students and clinical teachers from 15 Chilean medical schools analyzed an 80-item questionnaire built from perceptions of Chilean students and teachers from one medical school. After two Delfi rounds and a pilot application, a 48-item questionnaire was obtained. Its reliability and construct validity were assessed by Cronbach alpha coefficient and factor analysis, respectively, on the base of an application to 336 medical students. Results: The questionnaire developed, named CEACLIN, is highly reliable (alpha = 0.84). Its inner structure is made of eleven factors: Autonomy, Solving doubts and problems, Searching and organizing information, Proactivity, Reaching to others, Paying attention and emotions, Searching for trust, Evading burden, Coping with burden, Motivation and Postponing the personal life. All together, these factors account for 47.4 % of the variance. Conclusions: CEACLIN is a valid, reliable and easy to use instrument suited to identify students' strategies to learn in pre-clerkship years. Many of its items allude to concepts of theories of experiential learning and motivation. We hope that CEACLIN will be of value to medical students and clinical teachers to improve the learning and teaching of clinical reasoning and communication skills.
  • Thumbnail Image
    Item
    Clot lysis time in platelet-rich plasma: Method assessment, comparison with assays in platelet-free and platelet-poor plasmas, and response to tranexamic acid
    (TAYLOR & FRANCIS INC, 2012) Panes, Olga; Padilla, Oslando; Matus, Valeria; Saez, Claudia G.; Berkovits, Alejandro; Pereira, Jaime; Mezzano, Diego
    Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p < 0.0001). PFP- and PPP-, but more significantly PRP-CLT, were positively correlated with age and plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p < 0.001). All these CLT assays had no significant correlations with platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma cholesterol and its potential pathophysiologic and clinical relevance.
  • Thumbnail Image
    Item
    Development of ACLEEM questionnaire, an instrument measuring residents' educational environment in postgraduate ambulatory setting
    (2013) Riquelme Pérez, Arnoldo; Padilla, Oslando; Herrera, Cristián A.; Olivos, Trinidad; Román Brugnoli, José Antonio; Sarfatis Feige, Alberto; Torres, Patricio; Roff, Sue
  • No Thumbnail Available
    Item
    Dispositional Mindfulness Reduces Burnout and Promotes Flourishing in Medical Students: a Two-Wave Latent Change Score Model
    (2022) Zuniga, Denisse; Torres-Sahli, Manuel; Rigotti, Attilio; Pedrals, Nuria; Echeverria, Guadalupe; Padilla, Oslando; Lagos, Alejandra; McColl, Peter; Trucco, Olivia; Cisternas, Marcela; Gonzalez, Carolina; Bogado, Justo; Moraga, Ana Maria; Altamirano, Patricio; Duran, Esperanza; Mansilla, Marcela; Berrios, Carolina; Epstein, Ronald; Bitran, Marcela
    Objectives Many studies document the high prevalence of burnout among medical students. This syndrome may lead to depression, suicidal ideation, and increased academic dropout. However, there is a scarcity of evidence-based interventions to prevent it. The aim of this longitudinal study was to identify factors that may reduce students' burnout and foster their well-being, and upon which effective interventions can be developed. Methods A total of 1,117 medical students from eight Chilean universities were asked to complete a set of validated scales in 2015 and 2 years later, in 2017. The measures included distress, burnout, positive mental health, academic engagement, and dispositional mindfulness. Using logistic regressions and a two-wave latent change score model, the predictive power of these variables on burnout and flourishing (an optimal state of mental health) was studied, as well as their covariance across time. Results In total, 639 (57.2%) students answered the questionnaires in T1 and T2; 54.4% reported burnout in T1 and 56.2% in T2. Levels of dispositional mindfulness (the ability to pay attention to one's sensations, thoughts, and emotions in everyday life) predicted lower probabilities of burning out at 2 years, whereas having experienced burnout in T1 doubled these odds. Dispositional mindfulness, academic engagement, and flourishing at T1 predicted greater odds of flourishing 2 years later, while depression decreased these odds. Conclusions Dispositional mindfulness was the most powerful predictive factor of students' burnout and flourishing. As dispositional mindfulness can be nurtured through practice, incorporating mindfulness training into undergraduate medical programs may help reduce burnout and promote students' well-being as health professionals.
  • Thumbnail Image
    Item
    Estrategias del aprendizaje inicial de la clínica: más allá de los hábitos de estudio. Percepciones de estudiantes y docentes clínicos
    (2015) Zúñiga Parada, Denisse Alejandra; Leiva Rodríguez, Isabel; Calderon, Maribel; Tomicic S., Alemka; Padilla, Oslando; Riquelme Pérez, Arnoldo; Bitrán Carreño, Marcela
    Background: Teaching methods of the undergraduate medical curriculum change considerably from the first years to clinical training. Clinical learning occurs in complex and varied scenarios while caring for patients. Students have to adapt their learning approaches and strategies to be able to integrate theory and clinical practice and become experiential learners. Aim: To identify the strategies used by medical students to learn during the initial clinical years, as reported by students themselves and by their clinical tutors. Material and Methods: We performed eight focus group discussions with 54 students enrolled in years three to six and we interviewed eight clinical tutors. Both focus group discussions and interviews were audio recorded, transcribed and analyzed according to Grounded Theory. Results: Four main themes were identified in the discourse of both students and tutors: Strategies oriented to theoretical learning, strategies oriented to experiential learning, strategies for integrating theory and practice and strategies oriented to evaluation. The mentioning of individual differences was present across the reports of both students and tutors. Conclusions: Students use a rich variety of strategies to face the challenges of clinical learning. Both students and tutors recognize that the learning approaches and strategies vary according the nature of the task and individual differences. The responses of students bring particular knowledge of the approaches used for the theoretical and practical integration and delve into the social dimension of learning.
  • Thumbnail Image
    Item
    Evaluación de docentes clínicos de Postgrado: desarrollo y propiedades psicométricas del instrumento MEDUC-PG14
    (2015) Pizarro Rojas, Margarita Alicia; Solís, Nancy; Rojas, Viviana; Díaz, Luis Antonio; Padilla, Oslando; Letelier Saavedra, Luz María; Aizman, Andrés; Sarfatis Feige, Alberto; Olivos, Trinidad; Soza, Alejandro; Delfino, Alejandro; Latorre, Gonzalo; Ivanovic-Zuvic, Danisa; Hoyl, Trinidad; Bitrán Carreño, Marcela; Arab Verdugo, Juan Pablo; Riquelme Pérez, Arnoldo; Pizarro, Margarita; Solís, Nancy; Rojas, Viviana; Díaz, Luis Antonio; Padilla, Oslando; Letelier Saavedra, Luz María; Aizman, Andrés; Sarfatis Feige, Alberto; Olivos, Trinidad; Soza, Alejandro; Delfino, Alejandro; Latorre, Gonzalo; Ivanovic-Zuvic, Danisa; Hoyl, Trinidad; Bitrán Carreño, Marcela; Arab Verdugo, Juan Pablo; Riquelme Pérez, Arnoldo
  • Thumbnail Image
    Item
    Evaluation of the educational environment in medical specialty programs
    (SOC MEDICA SANTIAGO, 2012) Herrera, Cristian A.; Olivos, Trinidad; Roman, Jose Antonio; Larrain, Antonia; Pizarro, Margarita; Solis, Nancy; Sarfatis, Alberto; Torres, Patricio; Padilla, Oslando; Le Roy, Catalina; Riquelme, Arnoldo
    Background: The Postgraduate Hospital Education Environment Measure (PHEEM) questionnaire, is a valid and reliable instrument to measure the educational environment (EE) in postgraduate medical education. Aim: To evaluate the EE perceived by the residents of a postgraduate training program using the PHEEM. Material and Methods: The PHEEM was applied in 2010-2011 in 35 specialty programs. We calculated their individual results and compared means of both global and individual domain scores of the PHEEM, by gender, university of origin and nationality. Cronbach's alpha coefficients and D study (Generalizability theory) were performed for reliability. Results: Three hundred eighteen residents were surveyed (75.7% of the total universe). The mean score of the PHEEM was 105.09 +/- 22.46 (65.7% of the maximal score) which is considered a positive EE. The instrument is highly reliable (Cronbach's alpha = 0.934). The D study found that 15 subjects are required to obtain reliable results (G coefficient = 0.813). There were no significant differences between gender and university of origin. Foreigners evaluated better the EE than Chileans and racism was not perceived. The programs showed a safe physical environment and teachers with good clinical skills. The negative aspects perceived were a lack of information about working hours, insufficient academic counseling, and scanty time left for extracurricular activities. Conclusions: This questionnaire allowed us to identify positive aspects of the EE, and areas to be improved in the specialty programs. The PHEEM is a useful instrument to evaluate the EE in Spanish-speaking participants of medical specialty programs. (Rev Med Chile 2012; 140: 1554-1561).
  • No Thumbnail Available
    Item
    Exercise Challenge Test: Is a 15% Fall in FEV1 Sufficient for Diagnosis?
    (2011) Fuentes, Claudia; Contreras, Stefani; Padilla, Oslando; Castro-Rodriguez, Jose A.; Moya, Ana; Caussade, Solange
    Introduction. In the exercise challenge test (ECT), a drop in forced expiratory volume in the first second (FEV1) of between 10 and 15% is the determinant variable for a diagnosis of exercise-induced bronchospasm. Hypothesis. The use of FEV1 plus mean forced expiratory flow between 25% and 75% of the forced vital capacity (FEF25-75%) may increase the sensitivity of the ECT in asthmatic children. Specific objective. To compare FEV1 and FEF25-75% changes in a group of asthmatic and healthy children. Methodology. This was a cross-sectional study. Asthmatics were categorized by their severity (GINA) and after 1 month without controller therapy, an ECT was done under standard protocol. As well, a questionnaire about rhinitis and asthma was conducted with the entire population. ROC curves were used for analysis. Results. A total of 147 children (34 healthy and 113 asthmatics, 18 and 58 males, respectively) were evaluated. Divided into healthy children and intermittent, mild and moderate persistent asthmatics, they had similar average ages (9.4, 9.48, 8.97, and 11.2 years, respectively). Using a 15% fall in FEV1, we obtained 29% sensitivity and 100% specificity. However, when we used a 10% fall in FEV1, sensitivity was 47% and specificity was 97%. Adding a 28% fall in FEF25-75%, sensitivity was 52% and specificity was 94%. Conclusion. This study suggests that test sensitivity can increase by using a lower FEV1 cut-off (10%) and adding a 28% fall in FEF25-75%.
  • No Thumbnail Available
    Item
    Explanatory Model of Self-Efficacy for Cervical Cancer Screening
    (2024) Corrales, Angela-Cristina Yanez; Urrutia, Maria -Teresa; Padilla, Oslando
    Background: Cervical cancer (CC) screening is a public health concern, and social conditions partially explain the individual's ability to respond to the preventive aspect of the disease. This study aims to design an explanatory model of self-efficacy (SE) for CC screening. Methods: This study was conducted on 969 women aged 25-64 years who used the public health care system in Santiago, Chile. Multiple linear regression analysis was conducted to generate the explanatory model for global SE index and for each of their components as function of sociodemographic factors, factors related to interaction with the health system, risk factors for CC, family functioning, and the knowledge and beliefs of women regarding the disease and its prevention. Results: The factors that explain high levels of SE are low levels of education and knowledge of the risk factors of CC, better beliefs about the barriers to and benefits of a Papanicolaou (Pap) test, participation in breast cancer screening, and highly functional family Apgar. Conclusions: To administer as many CC screening as possible, achieve effective interventions, and reach optimal coverage rates, it is necessary to consider social determinants, collaborate with other cancer screening programs, and work toward the beliefs of the population.
  • Thumbnail Image
    Item
    Higher levels of insulin‐like growth factor‐1 in cord blood associate with risk of asthma at age 3
    (2023) Castro‐Rodríguez, José Antonio; Padilla, Oslando; Casanello, Paola; Forno, Erick
  • Thumbnail Image
    Item
    Human papillomavirus and Epstein-Barr virus infections in breast cancer from chile
    (2011) Padilla, Oslando; Solís, Luisa.; Corvalán R., Alejandro; Aguayo González, Francisco; Khan, Noureen.; Koriyama, Chihaya.; González, Carolina; Ampuero, Sandra.; Eizuru, Yoshito.; Akiba, Suminori.
    Abstract Background Human papillomavirus (HPV) and Epstein Barr virus (EBV) have been found in breast carcinomas (BCs) around the world. In this study, fifty-five BCs from Chile were analyzed for HPV and EBV presence. In addition, HPV-16 viral load/physical status and E6/E7 expressions were determined. Results The amplification of a housekeeping gene showed that 46/55 samples (84%) had amplifiable DNA. HPV-16 was detected in 4/46 BCs (8.7%) and EBV was detected in 3/46 (6.5%) BCs. The analysis of HPV-16 physical status showed that this virus was integrated in all of the tumors with a relatively low viral load (range: 0.14 to 33.8 copies/cell). E6 and E7 transcripts, however, were not detected in any HPV-16 positive specimens. Using a Cox-regression model, we found a statistically significant association between EBV presence and poor survival (p = 0.013). Conclusions The findings in this study suggest that it is unlikely that HPV and/or EBV play a direct role in the etiology of BC.Abstract Background Human papillomavirus (HPV) and Epstein Barr virus (EBV) have been found in breast carcinomas (BCs) around the world. In this study, fifty-five BCs from Chile were analyzed for HPV and EBV presence. In addition, HPV-16 viral load/physical status and E6/E7 expressions were determined. Results The amplification of a housekeeping gene showed that 46/55 samples (84%) had amplifiable DNA. HPV-16 was detected in 4/46 BCs (8.7%) and EBV was detected in 3/46 (6.5%) BCs. The analysis of HPV-16 physical status showed that this virus was integrated in all of the tumors with a relatively low viral load (range: 0.14 to 33.8 copies/cell). E6 and E7 transcripts, however, were not detected in any HPV-16 positive specimens. Using a Cox-regression model, we found a statistically significant association between EBV presence and poor survival (p = 0.013). Conclusions The findings in this study suggest that it is unlikely that HPV and/or EBV play a direct role in the etiology of BC.