Arnoldo Riquelme

Predictors of nonalcoholic steatohepatitis (NASH) in obese patients undergoing gastric bypass.

Background: Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are conditions gaining increasing recognition in hepatology as a potential cause of cirrhosis and end-stage liver disease. Obesity is one of the main risk factors. The aims of this study were to determine the frequency of NAFLD in obese patients and to identify variables that predict NASH. Methods: A prospective study was conducted of obese patients undergoing gastric bypass over a 20-month period. Assessment included liver function tests and evaluation of insulin resistance with the homeostatic model assessment (HOMA-IR). Liver biopsy was performed in all patients at the time of surgery. Clinical and biochemical variables were analyzed using a multivariate analysis to identify independent predictors of NASH. Results: 127 consecutive patients were included (62% female, 38% male, mean age 40±11 years, mean body mass index 42±6 kg/m2). Arterial hypertension was present in 52 patients (41%) and type 2 diabetes in 18 (14%). NAFLD was confirmed in 80 patients (63%), 47 (37%) had simple steatosis, and 33 (26%) had NASH. Cirrhosis was found in 2 patients corresponding to 1.6% of the total population. On multivariate analysis, AST >31 (IU/L) (OR 3.38, CI 1.17-9.8) and HOMA-IR >5.8 (OR 4.18, CI 1.39-12.49) independently predicted NASH. Conclusions: NAFLD is highly prevalent in morbidly obese patients. A high proportion of these patients exhibit NASH on histological examination. Insulin resistance represents the main predictor of NASH.

Saccharomyces cerevisiae fungemia after Saccharomyces boulardii treatment in immunocompromised patients.

Saccharomyces cerevisiae is widely used as a probiotic compound. Clinical data suggest that this agent is safe and effective. We report two cases of fungemia caused by S. cerevisiae occurring in immunosuppressed patients treated orally with S. boulardii Molecular typing confirmed clonality in isolate strains from patients and the capsule. Physicians caring for immunosuppressed patients must be aware of this potential serious complication of probiotic use.

Value of Adenosine Deaminase (ada) in Ascitic Fluid for the Diagnosis of Tuberculous Peritonitis: A Meta-analysis

Background and Goals Adenosine deaminase (ADA) levels are used for diagnosing tuberculosis in several locations and although many studies have evaluated ADA levels in ascitic fluid. These studies have defined arbitrary cut-off points creating difficulties in the clinical application of the results. The goals of this study are: to determine the usefulness of ADA levels in ascitic fluid as a diagnostic test for peritoneal tuberculosis (PTB) and define the best cut-off point. Study A systematic review was done on the basis of 2 independent searches. We selected prospective studies that included consecutive patients. Diagnosis of PTB had to be confirmed by bacteriologic or histologic methods and ADA levels determined by the Giusti method. Inclusion/exclusion criteria were applied by 2 independent reviewers. A receiver operating characteristic curve was constructed to establish the optimal cut-off point and the likelihood ratios (LRs) estimated using fixed-effect pooled method. Results Twelve prospective studies were found. Four of them met the inclusion criteria and were thus included in the meta-analysis. They included 264 patients, of which 50 (18.9%) had PTB. ADA levels showed high sensitivity (100%) and specificity (97%) using cut-off values from 36 to 40 IU/L. The included studies were homogeneous. Optimal cut-off point was determined at 39 IU/L, and LRs were 26.8 and 0.038 for values above and below this cut-off. Conclusions This study supports the proposition that ADA determination is a fast and discriminating test for diagnosing PTB with an optimal cut-off value of 39 IU/L.

Measuring the educational environment in health professions studies: A systematic review

Background: One of the determinants of the medical students behaviour is the medical school learning environment. Aim: The aim of this research was to identify the instruments used to measure the educational environment in health professions education and to assess their validity and reliability. Methods: We performed an electronic search in the medical literature analysis and retrieval system online (MEDLINE) and Timelit (Topics in medical education) databases through to October 2008. The non-electronic search (hand searching) was conducted through reviewing the references of the retrieved studies and identifying the relevant ones. Two independent authors read, rated and selected studies for the review according to the pre-specified criteria. The inter-rater agreement was measured with Kappa coefficient. Results: Seventy-nine studies were included with the Kappa coefficient of 0.79, which demonstrated a reliable process, and 31 instruments were extracted. The Dundee Ready Education Environment Measure, Postgraduate Hospital Educational Environment Measure, Clinical Learning Environment and Supervision and Dental Student Learning Environment Survey are likely to be the most suitable instruments for undergraduate medicine, postgraduate medicine, nursing and dental education, respectively. Conclusions: As a valid and reliable instrument is available for each educational setting, a study to assess the educational environment should become a part of an institutions good educational practice. Further studies employing a wider range of databases with more elaborated search strategies will increase the comprehensiveness of the systematic review.

Non‐alcoholic fatty liver disease and its association with obesity, insulin resistance and increased serum levels of C‐reactive protein in Hispanics

Background: Non‐alcoholic fatty liver disease (NAFLD) is a metabolic disorder of the liver, which may progress to fibrosis or cirrhosis. Recent studies have shown a significant impact of ethnicity on susceptibility to steatosis‐related liver disease.

The Problem of Helicobacter pylori Resistance to Antibiotics: A Systematic Review in Latin America

OBJECTIVES:Latin America has a high prevalence of Helicobacter pylori infection and associated diseases, including gastric cancer. Antibiotic therapy can eradicate the bacterial infection and decrease associated morbidity and mortality. To tailor recommendations for optimal treatments, we summarized published literature and calculated region- and country-specific prevalences of antibiotic resistance.METHODS:Searches of PubMed and regional databases for observational studies evaluating H. pylori antibiotic resistance yielded a total of 59 independent studies (56 in adults, 2 in children, and 1 in both groups) published up to October 2013 regarding H. pylori isolates collected between 1988 and 2011. Study-specific prevalences of primary resistance to commonly prescribed antibiotics were summarized using random-effects models. Between-study heterogeneity was assessed by meta-regression. As a sensitivity analysis, we extended our research to studies of patients with prior H. pylori-eradication therapy.RESULTS:Summary prevalences of antimicrobial primary resistance among adults varied by antibiotic, including 12% for clarithromycin (n=35 studies), 53% for metronidazole (n=34), 4% for amoxicillin (n=28), 6% for tetracycline (n=20), 3% for furazolidone (n=6), 15% for fluoroquinolones (n=5), and 8% for dual clarithromycin and metronidazole (n=10). Resistance prevalence varied significantly by country, but not by year of sample collection. Analyses including studies of patients with prior therapy yielded similar estimates. Pediatric reports were too few to be summarized by meta-analysis.CONCLUSIONS:Resistance to first-line anti-H. pylori antibiotics is high in Latin American populations. In some countries, the empirical use of clarithromycin without susceptibility testing may not be appropriate. These findings stress the need for appropriate surveillance programs, improved antimicrobial regulations, and increased public awareness.

Increased orocecal transit time in patients with nonalcoholic fatty liver disease.

Intestinal bacterial overgrowth (IBO) has been suggested to play a pathogenic role in patients with nonalcoholic fatty liver disease (NAFLD). Delayed intestinal transit may contribute to IBO development. Ten nondiabetic patients with NAFLD and abnormal liver enzymes were recruited. Ten healthy individuals, matched by sex, age, and body mass index, were used as controls. Orocecal transit time (OCTT) was measured by the lactulose breath test. Anti-endotoxin core antibodies (EndoCAb) were determined. The effect of oral norfloxacin (400 mg BID during 2 weeks) on liver enzymes, lactulose breath test, and EndoCAb was also studied. NAFLD patients had higher basal breathed H2 and prolonged OCTT compared to controls (127 ± 61 vs. 57 ± 23 min, respectively; P = 0.0037). EndoCAb titers were similar in NAFLD patients and controls. Norfloxacin administration had no effect on ALT levels, lactulose breath test, or EndoCAb titers in patients with NAFLD. The present data show evidence of deranged intestinal motility in nondiabetic patients with NAFLD and support the hypothesis that NAFLD could be linked to endotoxin-induced liver damage of intestinal origin.

Psychometric analyses and internal consistency of the PHEEM questionnaire to measure the clinical learning environment in the clerkship of a Medical School in Chile

Background and aims: The Spanish version of the Postgraduate Hospital Educational Environment Measure (PHEEM) was evaluated in this study to determine its psychometric properties, validity and internal consistency to measure the clinical learning environment in the hospital setting of Pontificia Universidad Católica de Chile Medical Schools Internship. Methods: The 40-item PHEEM questionnaire was translated from English to Spanish and retranslated to English. Content validity was tested by a focus group and minor differences in meaning were adjusted. The PHEEM was administered to clerks in years 6 and 7. Construct validity was carried out using exploratory factor analysis followed by a Varimax rotation. Internal consistency was measured using Cronbachs α. Results: A total of 125 out of 220 students responded to the PHEEM. The overall response rate was 56.8% and compliances with each item ranged from 99.2% to 100%. Analyses indicate that five factors instrument accounting for 58% of the variance and internal consistency of the 40-item questionnaire is 0.955 (Cronbachs α). The 40-item questionnaire had a mean score of 98.21 ± 21.2 (maximum score of 160). Conclusions: The Spanish version of PHEEM is a multidimensional, valid and highly reliable instrument measuring the educational environment among undergraduate medical students working in hospital-based clerkships.

Management of nonalcoholic fatty liver disease: An evidence-based clinical practice review

AIM To build a consensus among Chilean specialists on the appropriate management of patients with nonalcoholic fatty liver disease (NAFLD) in clinical practice. METHODS NAFLD has now reached epidemic proportions worldwide. The optimal treatment for NAFLD has not been established due to a lack of evidence-based recommendations. An expert panel of members of the Chilean Gastroenterological Society and the Chilean Hepatology Association conducted a structured analysis of the current literature on NAFLD therapy. The quality of the evidence and the level of recommendations supporting each statement were assessed according to the recommendations of the United States Preventive Services Task Force. A modified three-round Delphi technique was used to reach a consensus among the experts. RESULTS A group of thirteen experts was established. The survey included 17 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 93.8% in the first round and 100% in the second and third rounds. The final recommendations support the indication of lifestyle changes, including diet and exercise, for all patients with NAFLD. Proven pharmacological therapies include only vitamin E and pioglitazone, which can be used in nondiabetic patients with biopsy-proven nonalcoholic steatohepatitis (the progressive form of NAFLD), although the long-term safety and efficacy of these therapies have not yet been established. CONCLUSION Current NAFLD management is rapidly evolving, and new pathophysiology-based therapies are expected to be introduced in the near future. All NAFLD patients should be evaluated using a three-focused approach that considers the risks of liver disease, diabetes and cardiovascular events.

Overexpression of 11β-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue and portal hypercortisolism in non-alcoholic fatty liver disease.

The enzyme 11β‐hydroxysteroid‐dehydrogenase type 1 (11β‐HSD1) catalyses the reactivation of intracellular cortisol. We explored the potential role of 11β‐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. 11β‐HSD1 expression was also assessed in tissues from obese patients undergoing bariatric surgery.