Browsing by Author "Francisco Miquel, Juan"

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    A national online survey applied to patients with celiac disease in Chile
    (SOC MEDICA SANTIAGO, 2011) Espino, Alberto; Castillo L, Cecilia; Guiraldes, Ernesto; Santibanez, Helga; Francisco Miquel, Juan
    Background: Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Its prevalence in Europe and the USA is 0.5 to 1%. Aim: To analyze epidemiological aspect's and degree of compliance with gluten-free diet (GFD) among Chilean individuals with CD. Material and Methods: Subjects with confirmed or suspected CD were invited to answer an online survey published on the web at www.ftmdacionconvivir.cl. The answers were reinforced with a telephone interview. Results: The survey was answered by 1212 subjects (79% females). Median age at diagnosis was 25.8 years (range 1 to 84 years), with a bimodal curve with two peaks at less than 3 years and at 20 to 40 years of age. The diagnosis was made only by serologic markers in 9%, only by intestinal biopsy in 17.5%, and by a combination of both methods in 70%. Conditions associated with CD were reported by 30% of subjects and 20% had relatives with CD. The GFD was strictly adhered to by 70%, occasionally by 27% and never by 3%. Seventy five percent of subjects with a strict adherence to GFD had a favorable clinical response compared with 42% of those with incomplete or lack of adherence (odds ratio 4.0, 95% confidence intervals 2.8-5.7 p < 0.01). Conclusions: In 30% of respondents, the diagnosis of CD was not confirmed according to international guidelines that require serology and duodenal biopsy. One third of subjects recognized a poor compliance with GFD. Those with a strict adherence to it had a more favorable clinical course. However, 25% did not experience a clinical improvement despite a strict GFD, a finding which requires further study (Rev Med Chile 2011; 139: 841-847).
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    Diagnóstico y manejo de colitis ulcerosa grave. Una mirada actualizada
    (2017) Hernandez Rocha, Cristian; Ibanez, Patricio; Elena Molina, Maria; Klaassen, Julieta; Valenzuela, Andrea; Candia, Roberto; Bellolio, Felipe; Zuniga, Alvaro; Miguieles, Rodrigo; Francisco Miquel, Juan; Chianale, Jose; Alvarez Lobos, Manuel
    Ulcerative Colitis (UC) is a chronic inflammatory disease involving the colon, with alternating periods of remission and activity. Exacerbations can be severe and associated with complications and mortality. Diagnosis of severe UC is based on clinical, biochemical and endoscopic variables. Patients with severe UC must be hospitalized. First line therapy is the use of intravenous corticoids which achieve clinical remission in most patients. However, 25% of patients will be refractory to corticoids, situation that should be evaluated at the third day of therapy. In patients without response, cytomegalovirus infection must be quickly ruled out to escalate to second line therapy with biological drugs or cyclosporine. Total colectomy must not be delayed if there is no response to second line therapy, if there is a contraindication for second line therapies or there are complications such as: megacolon, perforation or massive bleeding. An active management with quick escalation on therapy allows to decrease the prolonged exposure to corticoids, reduce colectomy rates and its perioperative complications.
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    Phytosterol and cholesterol precursor levels indicate increased cholesterol excretion and biosynthesis in gallstone disease
    (WILEY-BLACKWELL, 2012) Krawczyk, Marcin; Luetjohann, Dieter; Schirin Sokhan, Ramin; Villarroel, Luis; Nervi, Flavio; Pimentel, Fernando; Lammert, Frank; Francisco Miquel, Juan
    In hepatocytes and enterocytes sterol uptake and secretion is mediated by Niemann-Pick C1-like 1 (NPC1L1) and ATP-binding cassette (ABC)G5/8 proteins, respectively. Whereas serum levels of phytosterols represent surrogate markers for intestinal cholesterol absorption, cholesterol precursors reflect cholesterol biosynthesis. Here we compare serum and biliary sterol levels in ethnically different populations of patients with gallstone disease (GSD) and stone-free controls to identify differences in cholesterol transport and synthesis between these groups. In this case-control study four cohorts were analyzed: 112 German patients with GSD and 152 controls; two distinct Chilean ethnic groups: Hispanics (100 GSD, 100 controls), and Amerindians (20 GSD, 20 controls); additionally an 8-year follow-up of 70 Hispanics was performed. Serum sterols were measured by gas chromatography / mass spectrometry. Gallbladder bile sterol levels were analyzed in cholesterol GSD and controls. Common ABCG5/8 variants were genotyped. Comparison of serum sterols showed lower levels of phytosterols and higher levels of cholesterol precursors in GSD patients than in controls. The ratios of phytosterols to cholesterol precursors were lower in GSD patients, whereas biliary phytosterol and cholesterol concentrations were elevated as compared with controls. In the follow-up study, serum phytosterol levels were significantly lower even before GSD was detectable by ultrasound. An ethnic gradient in the ratios of phytosterols to cholesterol precursors was apparent (Germans > Hispanics > Amerindians). ABCG5/8 variants did not fully explain the sterol metabolic trait of GSD in any of the cohorts. Conclusion: Individuals predisposed to GSD display increased biliary output of cholesterol in the setting of relatively low intestinal cholesterol absorption, indicating enhanced whole-body sterol clearance. This metabolic trait precedes gallstone formation and is a feature of ethnic groups at higher risk of cholesterol GSD. (HEPATOLOGY 2012)
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    The European lactase persistence genotype determines the lactase persistence state and correlates with gastrointestinal symptoms in the Hispanic and Amerindian Chilean population: a case-control and population-based study
    (BMJ PUBLISHING GROUP, 2011) Morales, Eugenia; Azocar, Lorena; Maul, Ximena; Perez, Claudio; Chianale, Jose; Francisco Miquel, Juan
    Background: The lactase persistent (LP) or lactase nonpersistent (LNP) state in European adults is genetically determined by a single nucleotide polymorphism (SNP) located 13.9 kb upstream of the lactase (LCT) gene, known as LCT C>T-13910 (rs4988235). The LNP condition leads to an inability to digest the milk sugar lactose leading to gastrointestinal symptoms and can affect nutrient and calcium intake in certain populations.