Browsing by Author "Riquelme, Arnoldo"

Now showing 1 - 20 of 26
  • Thumbnail Image
    Item
    A comprehensive approach to identify challenges for clinical reasoning development in undergraduate dental students and their potential solutions
    (WILEY, 2022) Isbej, Lorena; Fuentes-Cimma, Javiera; Veliz Paiva, Claudia; Valladares-Perez, Salvador; Riquelme, Arnoldo
    IntroductionClinical reasoning is a core competence in health professions that impacts the ability to solve patients' health problems. Due to its relevance, it is necessary to identify difficulties arising from different sources that affect clinical reasoning development in students. The aim of this study was to explore a comprehensive approach to identify challenges for clinical reasoning development in undergraduate dental students and their potential solutions. MethodsMixed methods were used in four stages: (1) students and clinical teachers focus groups to identify challenges to clinical reasoning development; (2) literature review to explore potential solutions for these challenges; (3) Delphi technique for teacher consensus on pertinence and feasibility of solutions (1-5 scale); and (4) teachers' self-perception of their ability to implement the solutions. ResultsThree categories and seven subcategories of challenges were identified: (I) educational context factors influencing the clinical reasoning process; (II) teacher's role in clinical reasoning development; and (III) student factors influencing the clinical reasoning process. From 134 publications identified, 53 were selected for review, resulting in 10 potential solutions. Through two Delphi rounds, teachers rated the potential solutions very highly in terms of relevance (4.50-4.85) and feasibility (3.50-4.29). Finally, a prioritisation ranking of these solutions was generated using their scores for relevance, feasibility, and teachers' self-perception of their ability to implement them. ConclusionsThe present comprehensive approach identified challenges for clinical reasoning development in dental students and their potential solutions, perceived as relevant and feasible by teachers, requiring further research and follow-up actions to address them.
  • 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
    Effects of Japanese herbal medicine inchin-ko-to on endotoxin-induced cholestasis in the rat
    (MEXICAN ASSOC HEPATOLOGY, 2009) Pablo Arab, Juan; Ramirez, Carolina; Munoz, Pablo; Pizarro, Margarita; Solis, Nancy; Riquelme, Arnoldo; Arrese, Marco
    Background/Objective. Inchin-ko-to (ICKT) is an herbal medicine used in Japan to treat jaundice and liver fibrosis. We investigated the effect of oral ICKT supplementation on endotoxin-induced cholestasis in the rat. Material and methods. Lipopolysaccharide (LPS) injection (1 mg/kg body weight i.p.) was used as a model of sepsis-induced cholestasis. Bite flow, biliary bile salt secretion, biliary glutathione secretion and protein expression of the main hepatobiliary transporters Na(+)-taurocholate-cotransporting peptide (Ntcp), multidrug resistance protein 2 (Mrp2) and bile salt export pump (Bsep) were analyzed by conventional techniques in ICKT treated and non-treated animals. Results. Injection of LIDS induced a significant decrease of bite ftow (-24%), biliary bite salts (-40%) and glutathione excretion (-70%) as well as a significant decrease in Ntcp (-90%) and Mrp2 (-80%) protein levels. ICKT supplementation partially prevented the effects of LIPS determining a less intense reduction in bile flow (-10%), a normalization of glutathione excretion as well as a significant increase in Mrp2 protein levels to 60% of the levels observed in control animals. ICKT administration did not modify the effects of LPS on BS secretion or Ntcp protein levels. Conclusion. Our data show that oral. supplementation of ICKT partially prevents LPS-induced cholestasis by increasing Mrp2 protein levels and biliary glutathione excretion thus increasing bite salt-independent ftow.
  • Thumbnail Image
    Item
    Endoscopic band ligation versus propranolol for the primary prophylaxis of variceal bleeding in cirrhotic patients with high risk esophageal varices
    (ELSEVIER ESPANA, 2010) Maria Perez Ayuso, Rosa; Valderrama, Sebastian; Espinoza, Manuel; Rollan, Antonio; Sanchez, Rene; Otarola, Francisco; Medina, Brenda; Riquelme, Arnoldo
    Background. Gastroesophageal variceal bleeding is a common complication of portal hypertension. Current guidelines recommend beta -blockers for primary prophylaxis. However, evidence suggests that endoscopic variceal ligation (EVL) reduce bleeding episodes. Aims. To compare endoscopic EVL with propranolol (PPL) for primary prophylaxis of variceal bleeding. Methods. We conducted a randomized controlled trial. Over a 9-year period, 75 patients with cirrhosis and high-risk esophageal varices (HREV) were recruited and allocated to EVL (n=39) or PPL (n=36). Primary outcome was variceal bleeding. Secondary outcomes were survival, source of bleeding and serious adverse events. Analyses were made by intention-to-treat. Results. Baseline characteristics were similar. Medium follow-up was 1647 1096 days. Complete follow-up was achieved in 85% of patients. Variceal bleeding occurred in 12% of EVL and in 25% of PPL group (p=0.17). The actuarial risks of bleeding after 2 years were similar in both groups. Overall mortality was 51% in EVL and 33% in PPL group (p=0.17). Patients in the EVL group showed a lower rate of esophageal variceal bleeding (5.1% v/s 25%, p=0.027) and a higher rate of subcardial variceal bleeding compared with PPL group (7.7% v/s 0%, p=0.027). Serious adverse events related to EVL occurred in 2 patients, including 1 death. Conclusions. The present study supports that PPL should be considered the first choice in primary prophylaxis of variceal bleeding offering similar effects and tower severe adverse events compared with EVL.
  • 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).
  • Thumbnail Image
    Item
    Experience of continuing online education in gastroenterology for non specialist medical doctors
    (SOC MEDICA SANTIAGO, 2019) Isbej, Lorena; Uribe, Javier; Carrasco, Olga; Villarroel, Isaac; Pizarro, Margarita; Isabel Jiron, Maria; Sanhueza, Edgar; Alvarez Lobos, Manuel; Hernandez Rocha, Cristian; Rollan, Antonio; Monsalve, Ximena; Antonio Diaz, Luis; Alejandra Cerda, Maria; Kramer, Tomas; Munizaga, Fernando; Riquelme, Arnoldo
    Background: Continuing education is essential for health professions and online courses can be a good way for professional development. Aim: To describe the experience with online courses for continuing education in hepatology and gastroenterology and to analyze their educational impact. Material and Methods: A three years' experience in courses on liver diseases and digestive tract is described. Their curricular design, methodology, and the educational impact was analyzed using the four levels of the Kirkpatrick's model. Results: On average, there were 321 students per course (2015-2017). 94% were Chilean and 6% from abroad (20 countries). In the educational impact analysis, in level 1 "reaction": 93% said that the course fulfilled their expectations and 92% would recommend it. In level 2 "learning": 42% approved the courses. Level 3 "behavior" was not evaluated and level 4 "organizational change" highlighted that the traditional face-to-face continuing education model of Chilean Gastroenterology Society (SChG) changed to full distance model in these three courses, with 1284 students from South America, Asia and Europe, in a 3-years-period. Additionally, these programs were included in the Medical Society of Santiago (SMS) continuing education agenda. Conclusions: The alliance between the SMS and the SChG generated on line courses that meet the educational needs of physicians and medical students, with excellent results and student perception.
  • No Thumbnail Available
    Item
    Induction of SARS-CoV-2 neutralizing antibodies by CoronaVac and BNT162b2 vaccines in naive and previously infected individuals
    (2022) Muena, Nicolas A.; Garcia-Salum, Tamara; Pardo-Roa, Catalina; Jose Avendano, Maria; Serrano, Eileen F.; Levican, Jorge; Almonacid, Leonardo, I; Valenzuela, Gonzalo; Poblete, Estefany; Strohmeier, Shirin; Salinas, Erick; Munoz, Andres; Haslwanter, Denise; Dieterle, Maria Eugenia; Jangra, Rohit K.; Chandran, Kartik; Gonzalez, Claudia; Riquelme, Arnoldo; Krammer, Florian; Tischler, Nicole D.; Medina, Rafael A.
    Interpretation The decay of nAbs titres in previously infected individuals over time indicates that vaccination is needed to boost humoral memory responses. Immunization of naydve individuals with two doses of CoronaVac induced nAbs titres that were significantly lower to that of convalescent patients, and similar to vaccination with one dose of BTN162b2. The real life effectiveness for CoronaVac in Chile was higher than estimated; indicating that lower titres and additional cellular immune responses induced by CoronaVac might afford protection in a highly immunized population. Nevertheless, the lower nAb titre induced by two doses of CoronaVac as compared to the BTN162b2 vaccine in naydve individuals, highlights the need of booster immunizations over time to maintain protec-tive levels of antibody, particularly with the emergence of new SARS-CoV-2 variants. Funding FONDECYT 1161971, 1212023, 1181799, FONDECYT Postdoctorado 3190706 and 3190648, ANID Becas/ Doctorado Nacional 21212258, PIA ACT 1408, CONICYT REDES180170, Centro Ciencia & Vida, FB210008, Finan-ciamiento Basal para Centros Cient?ficos y Tecnol?ogicos de Excelencia grants from the Agencia Nacional de Inves-tigaci?on y Desarrollo (ANID) of Chile; NIH-NIAD grants U19AI135972, R01AI132633 and contracts HHSN272201400008C and 75N93019C00051; the JPB Foundation, the Open Philanthropy Project grant 2020-215611 (5384); and by anonymous donors. The funders had no role in study design, data collection and analysis, deci-sion to publish, or preparation of the manuscript. Copyright (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
  • Thumbnail Image
    Item
    Influence of extrahepatic viral infection on the natural history of hepatitis C
    (ELSEVIER ESPANA, 2008) Ines Barria, Maria; Vera Otarola, Jorge; Leon, Ursula; Vollrath, Valeska; Marsac, Delphine; Riquelme, Arnoldo; Lopez Lastra, Marcelo; Soza, Alejandro
    HCV is primarily hepatotropic, but there is mounting evidence pointing to infection and replication of extrahepatic sites. Here we evaluated the occurrence of HCV infection of peripheral blood mononuclear cells (PBMC) and explored the possible association between viral extrahepatic infection and the natural history of the disease. Forty seven Chilean, HCV infected, treatment naive patients were included in the study. HCV RNA was isolated from plasma and PBMC and subsequently reverse transcribed, amplified and sequenced. Most patients harbored HCV 1b genotype and the most common route of infection showed to be blood transfusion. HCV RNA was readily detected in PBMCs of 34 out of the 47 patients (72%). We report that HCV sequences found in PBMC differ from those in plasma of the same subjects strongly suggesting HCV compartmentalization. In addition, we found that patients with detectable HCV RNA in PBMC had a tendency for being more likely cirrhotic [OR 3.8 (95 % CI: 0.98 to 14)]. In conclusion, this study provides further arguments for the existence of HCV infection of extrahepatic sites and suggests that extrahepatic infection could be a factor influencing the natural history of the disease.
  • Thumbnail Image
    Item
    Insulin resistance, hepatic steatosis and hepatitis C: A complex relationship with relevant clinical implications
    (ELSEVIER ESPANA, 2010) Arrese, Marco; Riquelme, Arnoldo; Soza, Alejandro
    Insulin resistance (IR) is a common pathophysiological condition where higher-than-normal concentrations of insulin are needed to maintain a normal glycemia and adequate glucose utilization in insulin target tissues. A high proportion (50-80%) of patients chronically infected with the hepatitis C virus (HCV) exhibit evidence of IR. Basic and clinical studies have disclosed a complex bidirectional relationship between IR and HCV infection that has important clinical implications. HCV infection may promote IR through direct viral-dependent mechanisms or due to activation of the inflammatory response resulting in increased production of Tumor Necrosis Factor-alpha and other cytokine-related molecules. These abnormalities may act synergistically with pre-existing metabolic risk factors and result in the development of hepatic steatosis and type 2 diabetes mellitus (T2DM) which are frequently found in the setting of HCV infection. Moreover, in addition to underlying metabolic abnormalities leading to its development hepatic steatosis also exhibit genotype-specific pathogenic mechanisms. A number of studies have shown that hepatic steatosis is associated to fibrosis progression in patients with HCV and that IR has a negative impact on the response rates to interferon-a-based therapy. Thus, modification of these factors through life-style changes or pharmacological agents may represent an undervalued specific target of therapy aiming to improve sustained virological response rates and reduce HCV related-morbidity and mortality.
  • Thumbnail Image
    Item
    Is PHEEM a multi-dimensional instrument? An international perspective
    (TAYLOR & FRANCIS LTD, 2009) Wall, David; Clapham, Mike; Riquelme, Arnoldo; Vieira, Joaquim; Cartmill, Richard; Aspegren, Knut; Roff, Sue
    Aim: To look at the characteristics of Postgraduate Hospital Educational Environment Measure (PHEEM) using data from the UK, Brazil, Chile and the Netherlands, and to examine the reliability and characteristics of PHEEM, especially how the three PHEEM subscales fitted with factors derived statistically from the data sets.
  • Thumbnail Image
    Item
    Measuring the educational environment in health professions studies: A systematic review
    (INFORMA HEALTHCARE, 2010) Soemantri, Diantha; Herrera, Cristian; Riquelme, Arnoldo
    Background: One of the determinants of the medical student's behaviour is the medical school learning environment.
  • No Thumbnail Available
    Item
    Mineralocorticoid receptor modulation by dietary sodium influences NAFLD development in mice
    (ELSEVIER ESPANA, 2021) Cabrera, Daniel; Rao, Isabel; Raasch, Fabiola; Solis, Nancy; Pizarro, Margarita; Freire, Mariela; De Urturi, Diego Saenz; Ramirez, Carolina A.; Triantafilo, Nicolas; Leon, Jonathan; Riquelme, Arnoldo; Barrera, Francisco; Baudrand, Rene; Aspichueta, Patricia; Arrese, Marco; Arab, Juan P.
    Introduction and Objectives: Nonalcoholic-fatty-liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome (MetS). Mineralocorticoid receptor (MR) activation is associated with increased risk of MetS but few studies have assessed the role of liver MR on NAFLD. We aimed to evaluate the effect of MR modulation by sodium intake in liver injury in experimental models of NAFLD.
  • Thumbnail Image
    Item
    Omicron variant Spike-specific antibody binding and Fc activity are preserved in recipients of mRNA or inactivated COVID-19 vaccines
    (2022) Bartsch, Yannic C.; Tong, Xin; Kang, Jaewon; Avendano, Maria Jose; Serrano, Eileen F.; Garcia-Salum, Tamara; Pardo-Roa, Catalina; Riquelme, Arnoldo; Cai, Yongfei; Renzi, Isabella; Stewart-Jones, Guillaume; Chen, Bing; Medina, Rafael A.; Alter, Galit
    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.
  • Thumbnail Image
    Item
    Optimal length of triple therapy for H pylori eradication in a population with high prevalence of infection in Chile
    (BAISHIDENG PUBLISHING GROUP INC, 2007) Riquelme, Arnoldo; Soza, Alejandro; Pedreros, Cesar; Bustamante, Andrea; Valenzuela, Felipe; Otarola, Francisco; Abbott, Eduardo; Arellano, Marco; Medina, Brenda; Pattillo, Alejandro; Greig, Douglas; Arrese, Marco; Rollan, Antonio
    AIM: To compare the efficacy of 7-d versus 14-d triple therapy for the treatment of H pylori infection in Chile, with a prevalence of 73% in general population. METHODS: H pylori-infected patients diagnosed by rapid urease test, with non-ulcer dyspepsia or peptic ulcer disease were randomized to receive omeprazole 20 mg bid, amoxicillin 1 g bid, and clarithromycin 500 mg bid for 7 (OAC7) or 14 (OAC14) d. Primary outcome was eradication rate 6 wk after the treatment. Subgroup analysis was carried out considering the eradication rate among patients with or without peptic ulcer disease and eradication rate among smokers or non-smokers.
  • Thumbnail Image
    Item
    Overexpression of 11 beta-Hydroxysteroid Dehydrogenase Type 1 in Hepatic and Visceral Adipose Tissue is Associated with Metabolic Disorders in Morbidly Obese Patients
    (SPRINGER, 2010) Baudrand, Rene; Carvajal, Cristian A.; Riquelme, Arnoldo; Morales, Mauricio; Solis, Nancy; Pizarro, Margarita; Escalona, Alex; Boza, Camilo; Perez, Gustavo; Dominguez, Angelica; Arrese, Marco; Fardella, Carlos E.
    The enzyme 11-beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) catalyzes intracellular glucocorticoid reactivation by conversion of cortisone to cortisol in different tissues and have been implicated in several metabolic disorders associated with obesity. The aim of this study was to evaluate the 11 beta-HSD1 expression in liver, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) in morbidly obese patients undergoing bariatric surgery and its correlations with clinical, anthropometric, and biochemical variables.
  • Thumbnail Image
    Item
    Overexpression of 11 beta-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue and portal hypercortisolism in non-alcoholic fatty liver disease
    (WILEY, 2012) Candia, Roberto; Riquelme, Arnoldo; Baudrand, Rene; Carvajal, Cristian A.; Morales, Mauricio; Solis, Nancy; Pizarro, Margarita; Escalona, Alex; Carrasco, Gonzalo; Boza, Camilo; Perez, Gustavo; Padilla, Oslando; Cerda, Jaime; Fardella, Carlos E.; Arrese, Marco
    Background: The enzyme 11 beta-hydroxysteroid-dehydrogenase type 1 (11 beta HSD1) catalyses the reactivation of intracellular cortisol. We explored the potential role of 11 beta-HSD1 overexpression in visceral adipose tissue (VAT) in non-alcoholic fatty liver disease (NAFLD) assessing sequential changes of enzyme expression, in hepatic and adipose tissue, and the occurrence of portal hypercortisolism in obese mice. 11 beta-HSD1 expression was also assessed in tissues from obese patients undergoing bariatric surgery. Methods: Peripheral and portal corticosterone levels and liver histology were assessed in ob/ob mice at two time points (8-12 weeks of age). 11 beta-HSD1 tissue expression was assessed in by RT-pcr in ob/ob mice and in 49 morbidly obese patients. Results: Portal corticosterone serum levels were higher in obese mice with a 26% decrease between 8 and 12 weeks of age (controls: 78.3 +/- 19.7 ng/ml, 8-week-old ob/ob: 167.5 +/- 14.5 ng/ml and 12-week-old ob/ob: 124.3 +/- 28 ng/ml, P < 0.05). No significant differences were found in peripheral corticosterone serum levels. Expression of 11b-HSD1 was lower in the liver [-45% at 8 weeks and -35% at 12-weeks (P = 0.0001)] and highly overexpressed in VAT in obese mice, compared to controls (128-fold higher in 8-week-old ob/ob and 41-fold higher in 12-week-old ob/ob, P < 0.01). No significant differences were seen in the expression of 11 beta-HSD1 in subcutaneous adipose tissue. In multivariate analysis, human 11 beta-HSD1 expression in VAT (OR: 1.385 +/- 1.010-1.910) was associated with NAFLD. Conclusion: Murine NAFLD is associated with portal hypercortisolism and 11 beta-HSD1 overexpression in VAT. In humans, 11 beta-HSD1 VAT expression was associated with the presence of NAFLD. Thus, local corticosteroid production in VAT may contribute to NAFLD pathogenesis.
  • No Thumbnail Available
    Item
    Overexpression of hepatic 5 alpha-reductase and 11 beta-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue is associated with hyperinsulinemia in morbidly obese patients
    (W B SAUNDERS CO-ELSEVIER INC, 2011) Baudrand Biggs Rene Felipe; Domínguez Ruiz-tagle, José Miguel; Carvajal, Cristian A.; Riquelme, Arnoldo; Campino, Carmen; Macchiavello, Stefano; Bozinovic, Milan; Morales, Mauricio; Pizarro, Margarita; Solis, Nancy; Escalona, Alex; Boza, Camilo; Arrese, Marco; Fardella, Carlos E.
    11 beta-Hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) converts cortisone to cortisol, mainly in the liver and visceral adipose tissue (VAT), and has been implicated in several metabolic disorders. The absence of systemic hypercortisolism in central obesity could be due to increased inactivation of cortisol to its tetrahydrometabolites by the hepatic enzymes 5 alpha-and 5 beta-reductases. Our aim was to assess the expression of the reductases in the liver and of 11 beta-HSD1 in the liver and VAT in morbidly obese patients and to analyze their association with clinical, anthropometric, and biochemical parameters. Hepatic and VAT samples were obtained during bariatric surgery. 5 alpha- and 5 beta-reductases, 11 beta-HSD1, and 18S expression was measured using real-time polymerase chain reaction. Anthropometric and biochemical variables were analyzed. Forty-one patients were recruited (age, 41.8 +/- 10.6 years; body mass index, 42.1 +/- 6.6 kg/m(2); 71% women). The expression of hepatic 5 alpha- and 5 beta-reductases was positively correlated (r = +0.53, P = .004), and their expression levels were correlated with hepatic 11 beta-HSD1 expression (r = +0.61, P < .001 for 5 alpha-reductase and r = +0.50, P < .001 for 5 beta-reductase). Hepatic 5 alpha-reductase was associated with insulin (r = +0.34, P = .015). Visceral adipose tissue 11 beta-HSD1 expression was associated with glucose (r = +0.37, P = .025) and insulin (r = +0.54, P = .002). Our results showed that 5 alpha-reductase and VAT 11 beta-HSD1 expressions were associated with insulinemia. These findings suggest that overexpression of 5 alpha-reductase, through a higher inactivation of cortisol in the liver, could have a protective role in preserving hepatic sensitivity to insulin. The overexpression of liver reductases in obesity could be an adaptive response to an increase in cortisol production by the liver and visceral 11 beta-HSD1 to avoid systemic hypercortisolism. (C) 2011 Elsevier Inc. All rights reserved.
  • Thumbnail Image
    Item
    Platelet count/spleen diameter ratio for non-invasive prediction of high risk esophageal varices in cirrhotic patients
    (ELSEVIER ESPANA, 2009) Barrera, Francisco; Riquelme, Arnoldo; Soza, Alejandro; Contreras, Alvaro; Barrios, Gerty; Padilla, Oslando; Viviani, Paola; Maria Perez Ayuso, Rosa
    Background and objective. Prophylaxis therapy is indicated in cirrhotic patients with large esophageal varices or small varices with red wale signs (high risk esophageal varices; HREV). Endoscopic surveillance to detect HREV is currently recommended. The objective of this study is to identify non-invasive predictors of HREV in cirrhotic patients. Design and methods. Adult cirrhotic patients without previous variceal bleeding were prospectively included. All patients underwent a complete biochemical workup, upper digestive endoscopy, and ultrasonographic measurement of spleen bipolar diameter. Platelet count/spleen diameter ratio (PC/SD) was calculated for all patients. The association of these variables with the presence of HREV in upper endoscopy was tested using univariate and multivariate analysis. Receiver operating characteristic (ROC) curves were constructed for variables associated with HREV. Results. Sixty-seven patients were included. The prevalence rate of HREV was 50%. Age, gender (female), platetet count, spleen diameter, PC/SD ratio, total bilirrubin, prothrombin activity (INR), Childl-Pugh score, clinical and ultrasonographic ascites were significantly associated with presence of HREV in univariate analysis. Age and PC/SD ratio were the parameters independently associated with HREV in a multivariate analysis, with OR 8.81 (CI 95%: 1.7-44.9) and OR 11.21 (CI 95%: 2.8-44.6) respectively. A PC/SD ratio cut-off value under 830.8 predicted HREV with 76.9% sensitivity, 74.2% specificity and 77.8% negative predictive value (ROC curve area: 0.78). Conclusions. The PC/SD ratio was significantly associated with HREV, but with suboptimal sensitivity and specificity. Therefore, the results of this study do not support the routine clinical use of PC/SD ratio for screening of HREV.
  • Thumbnail Image
    Item
    Portafolio en pregrado de Medicina: impacto educacional a 10 años de su implementación
    (2019) Reyes Placencia, Diego; Isbej Espósito, Lorena Pilar; Uribe Monasterio, Javier; Ruz Laurent, Cristian; Pizarro Rojas, Margarita; Walker Cruchaga María Rosa; Pérez Cruz, Pedro; Maldonado Morgado, Armando; Robles García, Camila; Latorre Selvat, Gonzalo; Ivanovic-Zuvic Seeger, Danisa; Figueroa, Catalina; González, Agustín; Cotoras Viedma, Petre; Núñez Palma, Carolina Verónica; Labarca L., Jaime; Riquelme, Arnoldo
  • Thumbnail Image
    Item
    Pro- and anti-inflammatory balance of septic patients is associated with severity and outcome
    (2007) Dougnac Labatut, Alberto; Castro López, Ricardo; Riquelme, Arnoldo; Calvo, M.; Eugenin, E.; Arellano, M.; Pattillo, A.; Regueira Heskia, Tomás; Mercado Flores, Marcelo Esteban; Andresen Hernández, Max Alfonso
    Purpose: To study infl ammatory profi le in patients with sepsis, severe sepsis and septic shock with regards to organ dysfunction and outcome, and to identify a pattern associated with more catastrophic course of illness, organ failure and risk of death. Material and methods: Twenty-nine consecutive patients with sepsis admitted to a medical Intensive Care Unit of a tertiary university hospital (November 2002-December 2003). Plasmatic levels of interleukin-6 (IL-6) and interleukin-10 (IL10) as pro-infl ammatory and anti-infl ammatory markers were measured at baseline, 12, 24 and 48 hours of evolution. Results: There is a positive association between higher levels of IL-6 and severity of the septic process, organ dysfunctions and risk of death, statistically signifi cant at anytime (at baseline, 12, 24 and 48 hours, p <0.05). Higher IL-6/IL-10 ratios associate signifi cantly with risk of death at 24 hours (RR=1.45 if higher or equal to the median). Conclusions: Plasmatic biomarkers measurement during the initial phase of sepsis may help to individualize therapy. An evaluation at 24 h based on IL-6/IL-10 ratio may anticipate a more aggressive infl ammatory profi le. These patients would specially benefi t from immunomodulating therapies to improve survival.