Browsing by Author "LLANOS, O"

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    ACCURACY OF THE 1ST ENDOSCOPIC PROCEDURE IN THE DIFFERENTIAL-DIAGNOSIS OF GASTRIC-LESIONS
    (1982) LLANOS, O; GUZMAN, S; DUARTE, I
    The accuracy of endoscopy and directed biopsy in the differential diagnosis of gastric lesions was evaluated by comparing the diagnoses of 1 endoscopic procedure (endoscopy and multiple directed biopsies) with the definitive diagnoses in 333 patients. The overall endoscopic and bioptic accuracy rate for all patients amounted to 98.8%. Separate accuracy rates of endoscopy alone and biopsy were 86.5 and 94.9%, respectively. The reliability of endoscopy was similar in the diagnosis of malignant and benign lesions (86 and 89%). Endoscopic biopsy was correct in 99.1% of benign lesions and in 86% of malignancies. False negative rates were 3.9% for endoscopy and 4.0% for biopsy. False positive rate was 5.5% for endoscopy alone and 2.1% for biopsy. One endoscopic procedure is a highly reliable method in the differential diagnosis of benign and malignant gastric lesions.
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    AXONAL SPROUTING INDUCED IN THE SCIATIC-NERVE BY THE AMYLOID PRECURSOR PROTEIN (APP) AND OTHER ANTIPROTEASES
    (1992) ALVAREZ, J; MORENO, RD; LLANOS, O; INESTROSA, NC; BRANDAN, E; COLBY, T; ESCH, FS
    Protease inhibition is the mechanism by which some trophic factors promote the extension of neurites. In the rat sciatic nerve, we assessed the ability to induce sprouts of the APP isoform that embodies the Kunitz antiprotease domain and other antiproteases. With the electron microscope, axonal sprouts were found when antiproteases were supplied but not after administration of inactive substances. We conclude that axons have a drive to sprout which can be released by the unbalance of an extracellular protease antiprotease system. We propose that this system is involved in the pathogenesis of Alzheimer's disease.
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    INTESTINAL METAPLASIA OF THE GASTRIC-MUCOSA IN AUTOPSIES OF CHILEAN ADULTS
    (1984) DUARTE, I; FONK, ML; LLANOS, O; GUZMAN, S
    The frequency and characteristics of intestinal metaplasia of the stomach were studied in autopsy material of 68 Chilean adults, with ages ranging from 30-79 yr. Metaplasia was found in 76.5%, which is in agreement with the high frequency of metaplasia reported from other geographic areas of high incidence for gastric cancer. Of those stomachs with metaplasia, 90.4% had involvement of the lesser curvature, 88.5% of the antral region and only 3.8% did not show the condition in those 2 areas. The metaplasia extended to less than 1/2 of the length of the mucosa in 85.6% of the sections with this change, showing that it is mainly a patchy and multifocal condition. In subjects older than 50 yr, intestinal metaplasia was more extended and severe, and involved with a relative higher frequency the greater curvature and both anterior and posterior walls of the stomach.
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    METAPLASIA AND PRECURSOR LESIONS OF GALLBLADDER CARCINOMA - FREQUENCY, DISTRIBUTION, AND PROBABILITY OF DETECTION IN ROUTINE HISTOLOGIC SAMPLES
    (1993) DUARTE, I; LLANOS, O; DOMKE, H; HARZ, C; VALDIVIESO, V
    Background. Gallbladder diseases, especially cholelithiasis, are extremely frequent in Chile, and an increasing frequency of gallbladder carcinoma has been observed during the last decades. Hyperplastic and atypical epithelial lesions of gallbladder epithelium have been considered potential precursors of invasive carcinoma. The current study was designed to study the frequency, distribution, extension, and probability of routine detection of potentially preneoplastic changes of gallbladder epithelium.
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    PATTERNS OF METASTASES IN INTESTINAL AND DIFFUSE TYPES OF CARCINOMA OF THE STOMACH
    (1981) DUARTE, I; LLANOS, O
    The pattern of the metastases in intestinal and diffuse types of gastric carcinoma were compared in 77 [human] autopsy cases. Differences in the extent of the dissemination, in the distribution of metastases and in the type of secondary involvement were found. The diffuse type of carcinoma showed a wider dissemination than the intestinal type. The intestinal type of carcinoma involved the liver more frequently and more extensively. Peritoneal metastases, lymphatic permeation of the lungs and Krukenberg tumors were more commonly found in cases of the diffuse type.