Browsing by Author "GONZALEZ, S"

Now showing 1 - 11 of 11
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    ACTINOMYCOSIS AND NOCARDIOSIS - A MORPHOLOGICAL-STUDY OF 17 CASES
    (1986) ODDO, D; GONZALEZ, S
    Actinomycosis and nocardiosis are bacterial infectious diseases with distinct morphologic features, that can be diagnosed in tissue sections. The clinico-pathologic features of 17 cases are reported with emphasis on their histopathologic diagnosis by using a simple combination of common tissue stains. Actinomycosis was frequently observed as a secondary and localized infection often with lung involvement, especially in residual cavities or bronchiectasis; in these cases numerous actinomycotic granules and only occasionally individual bacterial filaments within the suppurative foci and/or granulomas with suppurative centers were identified. Nocardiosis was observed as an opportunistic infection in the three cases studied; in these, isolated filaments of acid-fast and Gram-positive bacteria were observed. The morphologic features and the differential diagnosis in tissue sections of both infections are discussed with emphasis on their identification by the general pathologist in the routine material.
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    BENIGN FIBROUS HISTIOCYTOMA OF THE SKIN - AN IMMUNOHISTOCHEMICAL ANALYSIS OF 30 CASES
    (1985) GONZALEZ, S
    In this study the immunohistochemical analysis of distinct morphologic variants of benign fibrous histiocytoma (BFH) of the skin was performed with immunoperoxidase technique for both lysozyme and alpha-1-antitrypsin (A1AT). Thirty cases including cellular, fibrous and xanthomatous variants of BFH were selected. Out of the total 6 cases (20%) showed positive staining only for A1AT, 3 cases (10%) only for lysozyme and 10 (33.3%) for both markers. Thus, 19 cases (63.3%) showed positive staining for one of both markers. Positive staining was higher in the cellular variant than the fibrous and xanthomatous types. Negative staining of tumors of definite histiocytic morphology may be interpreted as a variable enzymatic expression of differet histiocytic activation and/or undetectable enzymatic content by the current techniques. These results are in accordance with our previous evolutional hypothesis of BFH which considered the cellular tumors as functionally more active variants evolving to less cellular, more fibrous and less active types. Current histogenetic concepts about this controversial group of skin neoplasms are discussed.
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    BILIARY LIPID SECRETION - IMMUNOLOCALIZATION AND IDENTIFICATION OF A PROTEIN ASSOCIATED WITH LAMELLAR CHOLESTEROL CARRIERS IN SUPERSATURATED RAT AND HUMAN BILE
    (1993) RIGOTTI, A; NUNEZ, L; AMIGO, L; PUGLIELLI, L; GARRIDO, J; SANTOS, M; GONZALEZ, S; MINGRONE, G; GRECO, A; NERVI, F
    Feeding a 0.5% diosgenin plus 0.02% simvastatin diet to rats increases biliary cholesterol concentration and saturation to levels generally found in human native supersaturated bile. By using preparative ultracentrifugation, gel filtration chromatography, and electron microscopy, we isolated, purified, and identified lamellar structures (unilamellar vesicles and multilamellae) as a major biliary cholesterol transport in supersaturated human and rat bile. It was estimated that more than 60% of biliary cholesterol is transported in these lamellar carriers, which were identified by transmission electron microscopy as unilamellar vesicles and multilamellar bodies within bile canaliculi of rats with cholesterol supersaturated bile. By SDS-PAGE, a characteristic and constant protein profile was found associated to the purified lamellar carriers. One of these proteins, a 130-kDa protein, was isolated from human biliary lamellae and used for preparation of a rabbit polyclonal antibody, which cross-reacted with the homologous rat protein. By Western blotting, it was established that the purified low density fraction of bile-Metrizamide gradients, containing lamellae, was enriched with the 130-kDa protein. The 130-kDa protein was characteristically detected at the canalicular membrane by Western blotting of hepatic subcellular fractions and by immunohistochemistry of rat and human liver biopsies. Amino acid sequencing of the amino terminus of the 130-kDa protein demonstrated a complete identity with aminopeptidase N, a canalicular transmembrane hydrophobic glycoprotein. These studies show that biliary lipids may acquire an ordered multilamellar structure that is present in the canaliculi of rats with supersaturated bile. These biliary lamellae are similar to lamellar bodies and surfactant-like material frequently found in other epithelia, suggesting common biogenetic, structural, and functional properties. The identification of aminopeptidase N associated with biliary lamellae is consistent with the involvement of the canalicular membrane in the secretory mechanism of biliary lipids.
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    EOSINOPHILIC GLOBULES IN PIGMENTED SPINDLE CELL NEVUS
    (1990) WISTUBA, I; GONZALEZ, S
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    IMMUNOLOGICAL EVALUATION OF PATIENTS WITH INVASIVE-CARCINOMA OF THE GALLBLADDER
    (1993) CUBILLOS, L; GONZALEZ, S; SEPULVEDA, C; RIVERO, S; CALVO, A; CARACCI, M; TORRES, J; TAPIA, A; ZUNIGA, J; FALCON, C; FERREIRO, O; MARTINEZ, I
    Forty-three patients with invasive adenocarcinoma of the gallbladder were postoperatively studied in order to determine their general immunological status as well as the local immunohistological reaction to the tumor. At the end of the follow-up, they formed two groups: 19 living patients (group GL) and 24 dead patients (group GD). As a control group (GC), 21 patients with cholecistectomy for cholelithiasis and without carcinoma were simultaneously evaluated. In GL, most of the tumors were limited to the gallbladder wall, and in GD, most of the tumors were already disseminated at the time of diagnosis. GD presented a lower percentage of peripheral blood B lymphocytes, as compared to GL and GC cases. Skin tests of delayed hypersensitivity were significantly more reactive in GL cases than in GD cases, and less reactive in GD than in GC cases. The immunohistological evaluation of the gallbladder yielded a lower B lymphocyte infiltration in GD tumors than in the control cases. GL cases showed a higher intratumoral lymphocytic and mononuclear cell infiltration than GD cases. Although the clinical stage was higher in GD than in GL cases, there were also significant differences in the local immune response and the general immunological status. Patients with invasive gallbladder adenocarcinoma showing longer postoperative survival revealed normal or increased local and general immunological reactions, whereas patients with disseminated tumors showed an important humoral and cellular secondary immunodeficiency.
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    MENINGOTHELIAL MENINGIOMA WITH AMIANTHOID FIBERS - CASE-REPORT WITH ULTRASTRUCTURAL-STUDY
    (GUSTAV FISCHER VERLAG, 1992) CHUAQUI, R; GONZALEZ, S; TORREALBA, G
    The case of a meningothelial meningioma with 'amianthoid' fibers in a 48-year-old woman is presented. By light microscopy the tumor showed the typical features of meningothelial meningioma and rounded, deeply eosinophilic, and fibrillary areas, especially around and/or in the vicinity of blood vessels. These fibers are also called 'amianthoid' fibers. Ultrastructurally, these foci were made up of disorderly arranged and interwaving mature collagen fibrils with a variable width between 40 and 190 nm. No evidence of intracellular collagen synthesis by the tumor cells was found. The presence of 'amianthoid' fibers does not seem to carry any prognostic significance.
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    MULTIDRUG RESISTANCE GENE AND P-GLYCOPROTEIN EXPRESSION IN GASTRIC ADENOCARCINOMA AND PRECURSOR LESIONS
    (1991) VOLLRATH, V; CHIANALE, J; GONZALEZ, S; DUARTE, I; ANDRADE, L; IBANEZ, L
    Overexpression of the Multiple Drug Resistance gene (MDR1) has been proposed as a major mechanism related to both intrinsic and acquired resistance to chemotherapeutic agents. The gene product is a membrane protein (P-glycoprotein), that acts as an energy-dependent drug efflux pump decreasing drug accumulation in resistant tumor cells. We have characterized MDR1 and P-Glycoprotein expression in human gastric adenocarcinoma and in precursor lesions. MDR1 mRNAs, analyzed by dot-blot technique, were detected in 9 of 10 non-tumoral gastric mucoase and in 8 of 10 gastric adenocarcinomas. Immunohistochemical analysis, using the MRK16 monoclonal antibody, revealed heterogeneous expression of P-Glycoprotein in individual cells. The P-Glycoprotein was found on the surface of cells of gastric areas with intenstinal metaplasia subtype III. This type of intestinal metaplasia, also called "colonic metaplasia", has been strongly associated with a high risk for the development of gastric cancer. The fact that the P-Glycoprotein was detected in this precursor lesion is consistent with the intestinal metaplasiadysplasia and carcinoma sequence proposed in the histogenesis of this tumor. The finding that P-Glycoprotein was heterogeneously expressed in malignant cells of some gastric adenocarcinomas also suggests that this transporter system probably contributes to primary and secondary multidrug resistance in this neoplasm.
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    PRIMARY CUTANEOUS ANGIOPLASMOCELLULAR HYPERPLASIA
    (LIPPINCOTT-RAVEN PUBL, 1995) GONZALEZ, S; MOLGO, M
    Two cases of solitary nodules on the skin of the trunk of young adults showing a peculiar pattern of proliferation of blood vessels and a mixed inflammatory infiltrate with predominance of polyclonal plasma cell infiltration are presented. Follow-up of these patients after complete surgical excision revealed no recurrence. We interpreted the lesions within the morphologic spectrum of plasma cell infiltrates of the skin to be reactive and/or hyperplastic, which we term primary cutaneous angioplasmocellular hyperplasia.
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    PROTECTIVE ROLE OF BILIARY CHOLESTEROL AND PHOSPHOLIPID LAMELLAE AGAINST BILE ACID-INDUCED CELL-DAMAGE
    (W B SAUNDERS CO-ELSEVIER INC, 1994) PUGLIELLI, L; AMIGO, L; ARRESE, M; NUNEZ, L; RIGOTTI, A; GARRIDO, J; GONZALEZ, S; MINGRONE, G; GRECO, AV; ACCATINO, L; NERVI, F
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    ULTRASTRUCTURE OF MESOTHELIAL REGENERATION AFTER INTRAPERITONEAL INJECTION OF ASBESTOS FIBERS ON RAT OMENTUM
    (1991) GONZALEZ, S; FRIEMANN, J; MULLER, KM; POTT, F
    In order to describe the ultrastructural features of the early phases of regenerating mesothelium in rat peritoneum, 69 cases were examined after intraperitoneal injection of 0.05-15 mg crocidolite, chrysotile B and other mineral and synthetic fibers. The findings show the presence of intermediate or transition cells between proliferating submesothelial connective tissue cells bearing the ultrastructural phenotype of myofibroblasts and mature fully regenerated mesothelium. Our results and data accumulated in the literature provide strong support for the hypothesis of submesothelial cell origin for regenerating mesothelium.