Browsing by Author "Duarte, I"

Now showing 1 - 13 of 13
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    A comparative study between the gastric mucosa of Chileans and ether dwellers of the Pacific basin
    (1996) Rubio, CA; Pisano, R; Llorens, P; Duarte, I
    A total of 3,289 sections of 120 gastrectomy specimens from Chile were reviewed. Intramucosal cysts were found in 61.7% of the specimens, ciliated metaplastic cells in 33.3%, large vacuolated cells in 20.8% and extensive intestinal metaplasia in 51.7%. The frequency of these non-neoplastic changes was significantly higher in specimens with early adenocarcinoma of intestinal type than in those with early adenocarcinoma of diffuse type or having a peptic ulcer. Similar results have been recorded in other inhabitants of the Pacific basin, but not in inhabitants of the Atlantic basin. Interestingly, the gastric cancer incidence in the various populations studied in the Pacific basin is much higher than in those studied in the Atlantic basin. Environmental factors acting in Chile appear to have induced those non-neoplastic changes in the gastric mucosa. The question arises as to whether environmental factors (promoters?) acting in Chile (as well as in Japan, in Hawaii and in New Zealand) have favored the necessary non-neoplastic mucosal conditions required for the subsequent development of gastric adenocarcinoma (in particular of intestinal type).
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    Accuracy of invasive and noninvasive tests to diagnose Helicobacter pylori infection after antibiotic treatment
    (WILLIAMS & WILKINS, 1997) Rollan, A; Giancaspero, R; Arrese, M; Figueroa, C; Vollrath, V; Schultz, M; Duarte, I; Vial, P
    Objectives: To compare the diagnostic accuracy of the most widely available tests for diagnosis of Helicobacter pylori infection after antibiotic treatment, Methods: A total of 59 H, pylori-positive, duodenal ulcer patients (mean age, 40.7 +/- 11.7 yr; 40 male and 19 female) were treated for 2 wk with either amoxicillin-metronidazole (n = 36) or omeprazole-amoxicillin-tinidazole (n = 23), and after 4 wk, were tested for H, pylori infection by [C-14]urea breath test (UBT), serum IgG antibody level, and multiple antral biopsies for rapid urease testing, histology, Warthin-Starry stain, and polymerase chain reaction to detect H, pylori DNA, Infection status was established by a concordance of test results, Results: H, pylori was eradicated in 47 patients (80%), UBT and rapid urease testing had the best sensitivity and specificity, although not statistically different to Warthin-Starry stain and polymerase chain reaction, Serology and histology had little diagnostic value in this setting due to high proportion of false-positive results, Conclusions: Noninvasive UBT is as accurate in predicting H, pylori status after antibiotic treatment as rapid urease testing and Warthin-Starry stain, Especially for duodenal ulcer patients, UBT could be considered the gold standard to confirm eradication of H, pylori.
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    Bile secretory function in the obese Zucker rat: evidence of cholestasis and altered canalicular transport function
    (BMJ PUBLISHING GROUP, 2004) Pizarro, M; Balasubramaniyan, N; Solis, N; Solar, A; Duarte, I; Miquel, JF; Suchy, FJ; Trauner, M; Accatino, L; Ananthanarayanan, M; Arrese, M
    Background: Obese Zucker rats (ZR) have been used as an experimental model for non-alcoholic fatty liver disease and are particularly susceptible to various types of liver injury. Bile secretory function has not been assessed in ZR.
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    CagA antibodies as a marker of virulence in Chilean patients with Helicobacter pylori infection
    (2003) Harris, PR; Godoy, A; Arenillas, S; Riera, F; García, D; Einisman, H; Peña, A; Rollán, T; Duarte, I; Guiraldes, E; Perez-Perez, G
    Background: The bacterial and host factors that influence the clinical outcomes of the Helicobacter pylori infection have not been fully identified. Cytotoxin-associated gene product (CagA), one of the virulence factors, has been associated with a more aggressive form of infection. The authors studied the relationship between CagA status and clinical outcome in Chilean children and adults with H. pylori infection.
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    Histological resolution of steatohepatitis after iron depletion
    (2004) Riquelme, A; Soza, A; Nazal, L; Martínez, G; Kolbach, M; Patillo, A; Arellano, M; Duarte, I; Martínez, J; Molgó, M; Arrese, M
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    Microsatellite analysis of synchronous and metachronous tumors - A tool for double primary tumor and metastasis assessment
    (2003) Tang, MY; Pires, Y; Schultz, M; Duarte, I; Gallegos, M; Wistuba, II
    Despite well-established histopathological features and the development of immunostaining of human neoplasms, there are a number of cases in which surgical pathologists cannot assure the origin of synchronous and metachronous tumors. In many cases, the classification of these lesions as either two separate primary tumors or as a single primary tumor with a metastasis has significant implications with respect to patient prognosis and recommendations for therapy. To establish the origin of tumors, we assessed tumor cell clonality using PCR-based microsatellite analysis on microdissected archival tissues for loss of heterozygosity (LOH) and microsatellite instability (NISI) in a series of 19 paired synchronous and metachronous tumors from several organs. As a control group, 15 autopsy cases with an unequivocally recognizable primary tumor and associated metastases were also examined. Based on LOH and MSI findings, and using a panel of 4 to 12 (median 7) microsatellite markers, we were able to establish the clonal pattern of microsatellite changes in 17 out of 19 (89%) biopsy cases and thus determine if they were either double primary tumors (41%) or metastases (59%). Of interest, identical or similar pattern of microsatellite abnormalities were detected in 15 primary tumors and corresponding metastasis from autopsies. Our results indicate that microsatellite analysis for LOH and MSL as an expression of clonality, provides a useful tool to distinguish double primary neoplasms and metastases in synchronous and metachronous tumors.
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    Nature and extent of gastric lesions in symptomatic Chilean children with Helicobacter pylori-associated gastritis
    (WILEY, 2002) Guiraldes, E; Pena, A; Duarte, I; Trivino, X; Schultz, M; Larrain, F; Espinosa, MN; Harris, P
    Chile has one of the highest rates of gastric cancer in the world and most children and adolescents in the country are colonized by Helicobacter pylori. This study assessed the nature and extent of the gastric lesions in 73 consecutive patients aged 5-17 y, referred for upper gastrointestinal endoscopy. Their H. pylori-associated gastric pathology was characterized and these data were compared with their sociodemographic status. Endoscopic assessment was normal in 43 patients while in 30 there was a variety of mucosal lesions. Sixty patients (83%) had histological chronic gastritis of the antrum and in 45 (63%) the lesions also involved the gastric corpus; 90% of patients with chronic gastritis were colonized by H. pylori. Although most of these patients had epithelial erosions and dedifferentiation of the pit epithelium, atrophy and metaplasia were not found. Patients' socioeconomic status was inversely correlated with their rate of colonization by H. pylori (p < 0.005), the frequency of gastric lesions on endoscopy (p < 0.01) and the frequency of involvement of antral and corpus mucosa by chronic gastritis (p < 0.002). This latter feature was positively correlated with age (p < 0.001).
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    Predictors of nonalcoholic steatohepatitis (NASH) in obese patients undergoing gastric bypass
    (2005) Boza, C; Riquelme, A; Ibañez, L; Duarte, I; Norero, E; Viviani, P; Soza, A; Fernandez, JI; Raddatz, A; Guzman, S; Arrese, M
    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.
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    Proinflammatory cytokine expression in gastric tissue from children with Helicobacter pylori-associated gastritis
    (LIPPINCOTT WILLIAMS & WILKINS, 2001) Guiraldes, E; Duarte, I; Pena, A; Godoy, A; Espinosa, MN; Bravo, R; Larrain, F; Schultz, M; Harris, P
    Background: Helicobacter pylori infection of the gastric mucosa in humans is usually acquired early in life. The chronic inflammation that ensues involves the increased production of inflammatory cytokines. Published data on production of these mediators by gastric mucosa of H. pylori-infected children are few.
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    Refractory enteric amebiasis in pediatric patients with acute graft-versus-host disease after allogeneic bone marrow transplantation
    (LIPPINCOTT WILLIAMS & WILKINS, 2000) Perret, C; Harris, PR; Rivera, M; Vial, P; Duarte, I; Barriga, F
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    Results of surgical treatment of gastric cancer
    (1999) Llanos, O; Guzman, S; Pimentel, F; Ibañez, L; Duarte, I
    Background/Aim: The extent of gastric resection and the role of lymphadenectomy in the treatment of gastric cancer are controversial. Methods: This study evaluates the results of radical gastric resection (D2 lymphadenectomy) in 375 patients with a gastric carcinoma operated according to a prospective protocol, Results: Total gastrectomy was performed in 196 and a subtotal gastrectomy in 179 patients, with an operative mortality of 3.5 and 2.8%. The presence of lymph node metastasis was related to the depth of the tumor in the gastric wall. The cumulative 5-year survival was dependent on the depth of tumoral invasion in the gastric wall and also on the presence of lymphatic metastasis. Curative resection had a significantly better 5-year survival (72%) than noncurative resection (26%). Conclusion: Although it is difficult to prove the benefits of extended lymphadenectomy in the surgical treatment of gastric carcinoma, the results of these series seem to support its usefulness. Copyright (C) 1999 S. Karger AG, Basel.
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    Survival of young patients after gastrectomy for gastric cancer
    (2006) Llanos, O; Butte, JM; Crovari, F; Duarte, I; Guzmán, S
    It has been suggested that gastric cancer has a worse prognosis in young patients, but the data are controversial. The aim of this study was to compare the 5-year survivals after gastrectomy for gastric cancer in two groups of patients (those <= 45 years of age and those (> 45 years) and to determine some of the prognostic factors. The 5-year survival was significantly better for patients <= 45 years of age. Survival was also better for young patients with a curative resection and also for those with lymph node metastases. However, survival was not significantly different for the two groups when the resection was not curative and when the lymph nodes were not involved. Survival was no different for the two groups when compared at each stage, although a multivariate analysis showed that age > 45 years, moderate or poor degree of differentiation of the tumor, advanced tumors, the presence of lymph node involvement, and a noncurative resection were independent negative prognostic factors. Long-term survival after gastrectomy for gastric cancer depends on the stage of the disease; the age of the patient is not a decisive factor.
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    The long-term reinfection rate and the course of duodenal ulcer disease after eradication of Helicobacter pylori in a developing country
    (2000) Rollan, A; Giancaspero, R; Fuster, F; Acevedo, C; Figueroa, C; Hola, K; Schulz, M; Duarte, I
    OBJECTIVE: The aim of this study was to evaluate the effect of Helicobacter pylori (H. pylori) eradication on the natural history of duodenal ulcer disease and the reinfection rate after treatment in a developing country.