Browsing by Author "Alvarez Lobos, Manuel"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Clostridium difficile associated infections: an updated view
    (SOC CHILENA INFECTOLOGIA, 2012) Hernandez Rocha, Cristian; Naour, Sebastian; Alvarez Lobos, Manuel; Paredes Sabja, Daniel
    Clostridium difficile is an emerging anaerobic, spore forming pathogen, recognized as the etiological agent of similar to 30% of antibiotic associated diarrheas. Clinical symptoms can fluctuate from mild to moderate diarrhea, pseudomembranous colitis and toxic megacolon. The incidence of C. difficile associated infections (CDAI) is similar to 1% of total hospitalized patients. CDAI has a mortality rate of similar to 1 to 5%, and a relapse rate of similar to 20%. The appearance of severe outbreaks of CDAI could be attributed to changes in the production of the two major virulence factors, the enterotoxins TcdA and TcdB, which produce massive epithelial damage. C. difficile spores play an essential role in transmission, initiation and persistence of CDAI. Recent advances in detection methods, development of novel therapies and prevention methods could allow a reduction on the frequency of CDAI. The objective of this review is to provide an updated view on the mechanisms of pathogenesis, epidemiology, risk factors, detection methods, treatment and prevention of CDAI.
  • Thumbnail Image
    Item
    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.
  • 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.
  • Thumbnail Image
    Item
    Increased production of soluble TLR2 by lamina propria mononuclear cells from ulcerative colitis patients
    (ELSEVIER GMBH, 2012) Candia, Enzo; Diaz Jimenez, David; Langjahr, Patricia; Nunez, Lucia E.; de la Fuente, Marjorie; Farfan, Nancy; Lopez Kostner, Francisco; Abedrapo, Mario; Alvarez Lobos, Manuel; Pinedo, George; Beltran, Caroll J.; Gonzalez, Carlos; Gonzalez, Maria Julieta; Quera, Rodrigo; Hermoso, Marcela A.
    Toll-like receptor 2 (TLR2) is a type I pattern recognition receptor that has been shown to participate in intestinal homeostasis. Its increased expression in the lamina propria has been associated with the pathogenesis in inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn's disease (CD). Recently, soluble TLR2 (sTLR2) variants have been shown to counteract inflammatory responses driven by the cognate receptor. Despite the evident roles of TLR2 in intestinal immunity, no study has elucidated the production and cellular source of sTLR2 in IBD. Furthermore, an increase in the population of activated macrophages expressing TLR2 that infiltrates the intestine in IBD has been reported. We aimed first to assess the production of the sTLR2 by UC and CD organ culture biopsies and lamina propria mononuclear cells (LPMCs) as well as the levels of sTLR2 in serum, and then characterize the cell population from lamina propria producing the soluble protein.
  • Thumbnail Image
    Item
    Phenotype and genotype of thiopurine methyltransferase in Chilean individuals
    (SOC MEDICA SANTIAGO, 2012) Jorquera, Andres; Solari, Sandra; Vollrath, Valeska; Guerra, Irene; Chianale, Jose; Cofre, Colomba; Kalergis, Alexis; Ibanez, Patricio; Bueno, Susan; Alvarez Lobos, Manuel
    Background: Thiopurines (azathioprine and 6-mercaptopurine) are highly effective medications but with potential adverse effects. Thiopurine methyltransferase (TMPT) is the key enzyme in their pharmacokinetics and is genetically regulated. A low activity of TPMT is associated with myelotoxicity. The genotype and enzyme activity can vary by ethnicity. Aim: To study the activity and genotype of TPMT in a group of Chilean subjects. Material and Methods: In 200 healthy adult blood donors, TPMT activity was determined by high performance liquid chromatography (HPLC). Deficient, low, normal or high levels were defined when enzymatic activity was <= 5, 6-24, 25-55 and >= 56 nmol/grHb/h, respectively. Genotyping of TPMT ((star)1, (star)2, (star)3A, (star)3B, (star)3C) was performed by PCR. Results: Seventy seven women (38.5%) and 123 men (61.5%), with an average age of 34.9 years were studied. Eighteen subjects (9%) had a low enzymatic activity, 178 (89%) had normal activity, 4 (2%) had high activity and no genotype deficient subjects were identified. The wild type genotype ((star)1) was found in 184 (92%) individuals and 16 (8%) were heterozygous for the variants: (star)2 (n = 2), (star)3A (n = 13) and (star)3C (n = 1). No homozygous subjects for these variants were identified. Wild type genotype had an increased enzymatic activity (40.8 +/- 7.2 nmol/gHb/h) compared to heterozygous group (21.2 +/- 3 nmol/gHb/h; p < 0.001). Conclusions: Less than 10% of a Chilean population sample has a low enzymatic activity or allelic variants in the TPMT gene, supporting the use of thiopurines according to international recommendations. (Rev Med Chile 2012; 140: 889-895).
  • Thumbnail Image
    Item
    Soluble ST2: A new and promising activity marker in ulcerative colitis
    (BAISHIDENG PUBL GRP CO LTD, 2011) Diaz Jimenez, David; Nunez, Lucia E.; Beltran, Caroll J.; Candia, Enzo; Suazo, Cristobal; Alvarez Lobos, Manuel; Gonzalez, Maria Julieta; Hermoso, Marcela A.; Quera, Rodrigo
    AIM: To correlate circulating soluble ST2 (sST2) levels with the severity of ulcerative colitis (UC) and serum levels of pro-inflammatory cytokines, and to demonstrate the predictive power of sST2 levels for differentiation between active and inactive UC.