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G Viale

Publications and source records attributed to G Viale.

At least 163 records · Page 9Linked to original sources
PubMed1987

Gangliocytic paraganglioma of the duodenum: case report.

A case of gangliocytic paraganglioma of the second portion of the duodenal loop is presented. The tumor was polypoid and, histologically, composed of mature ganglion cells, spindle cells and epithelial-like cells. Immunocytochemical examination demonstrated the presence of neurofilament 200 K and S-100 protein only in the first two types of cells; all the cells were positive for neuron-specific enolase. The reaction for cytokeratin was negative in all neoplastic components. According to morphologic and immunocytochemical findings, we suggest a hamartomatous nature of this entity.

Adult↗
PubMed1987

Ultrastructural immunolabeling in renal diseases. Past, present and future expectations.

The use of immunoelectron microscopy in the evaluation of renal diseases represents a valuable addition to existing techniques. The ability to immunolabel immune-complex deposits for light- and heavy-chain determinants, and complement fractions virtually eliminates the need for traditional immunofluorescence. One of the main advantages of performing immunoelectron microscopy relates to the fact that immunologic events can be adequately correlated morphologically with the degree and type of tissue reactions in the various renal compartments. Immunopathogenetic mechanisms can be clearly evaluated with this technique. The need to submit specimens in different fixatives is eliminated and all diagnostic modalities can be performed on a single fragment of tissue. The examination of the thick sections prepared from plastic-embedded tissue for survey provides excellent material for interpretation of findings at the light-microscopic level. These sections can be stained with hematoxylin/eosin, trichrome, silver methenamine and PAS stains with excellent results. The time and resources needed for processing renal biopsies can be significantly reduced by utilizing the proposed methodology. Likewise, interpretation of results may benefit from utilization of the same fragment for all diagnostic modalities.

Complement System Proteins↗
PubMed1987

Choroid plexus tumors. An immunocytochemical study with particular reference to the coexpression of intermediate filament proteins.

Sixteen choroid plexus tumors (CPTs) have been investigated for the localization of different immunocytochemical markers of epithelial and nonepithelial nature, namely, simple epithelial-type cytokeratins, vimentin, glial fibrillary acidic protein (GFAP), a panepithelial antigen defined by the lu-5 monoclonal antibody (lu-5 antigen), S-100 protein, and epithelial membrane antigen (EMA). Intermediate filament proteins have been identified in paraffin sections of 14 of 16 cases (87.5%). In all these tumors, cytokeratins and vimentin were constantly coexpressed by the neoplastic cells, in a manner similar to that of the cells lining normal choroid plexus. In 7 of these 14 cases, in addition to cytokeratins and vimentin, the neoplastic cells were shown to coexpress GFAP, which is not synthesized by their normal cell counterpart. The appearance of GFAP immunoreactivity in CPTs might be related to an ependymal differentiation of the neoplastic cells, because normal ependyma and ependymomas constantly coexpress GFAP and vimentin. The simultaneous expression of three distinct intermediate filament proteins by the same neoplastic cells is an exceedingly rare phenomenon, which has never been reported by double labeling technique in neoplasms of the central nervous system. Despite the complex antigenic profile of the CPT, which includes immunoreactivity for lu-5 antigen, S-100 protein, and EMA in most of the cases, positivity for three different epithelial markers indicates that these tumors have an epithelial nature. Moreover, the immunocytochemical typing of CPT with the panel of antibodies used in the current investigation allows differentiation from other primary and metastatic central nervous system tumors.

Antibodies, Monoclonal↗
PubMed1986

Plasma cell granuloma of the lung (inflammatory pseudotumor).

A case of plasma cell granuloma (PCG) of the lung in a 54-year old man is reported. PCG is a rare benign lesion that usually presents as a solitary nodule in the lung (coin lesion) at routine X-ray examination. Microscopically it consists of a granulomatous tissue where the major components are mature plasma cells. The immunohistochemical demonstration of polyclonality of plasma cells, excluding the diagnosis of plasmacytoma, confirms the inflammatory pseudotumoral nature of this lesion, although the etiology remains obscure. The presence of lymphocytes, histiocytes, macrophages, blood vessels with prominent endothelial cells and peripheral sclero-hyalinized connective tissue may pose problems in the differential diagnosis with sclerosing hemangioma, pseudolymphoma, nodular amyloidosis, pulmonary hyalinizing granuloma, chronic abscess and neoplasms of true histiocytic origin. The term inflammatory pseudotumor is preferable in describing this type of lesion.

Diagnosis, Differential↗
PubMed1986

The commitment of secretory cells to the selective expression of immunoglobulin CH genes is determined by the available concentrations of the triggering ligand.

The property of lipopolysaccharide to induce B cells to both proliferate and differentiate to IgM, IgG3 and IgG2b expression can be ascribed either to a precommitted sequence of molecular events in the activated B cells or, alternatively, to separate activities which independently modulate the two events. To discriminate between these two possibilities we have investigated the relationship between the doses of the polyclonal stimulus and the commitment of the activated cells to proliferate and to produce various isotypes. Low doses of ligand supported proliferation as well as IgM but not IgG2b secretion. On the contrary, high doses of the same ligand were less efficient in supporting proliferation but strongly induced heavy chain class switch. The effect of lipopolysaccharide concentrations on CH genes expression decayed with the distance from mu to the respective C gamma gene. Although we could define different B cell subsets on the basis of their proliferative response to various doses of the ligand, all these B subpopulations were found to be multipotential in terms of their switching capacity. Taken together our data show that in lipopolysaccharide cultures B cell proliferation and heavy chain switch are two events completely dissociable on the basis of their inducing requirements.

Animals↗
PubMed1986

Ultrastructural localization of extracellular immunoglobulins in immune-complex-mediated glomerulonephritis. Immunoelectron microscopy of Epon-embedded human renal biopsies using the immunogold staining procedure.

The ultrastructural localization of immunoglobulins (Igs) in immunologically mediated glomerulonephritis was achieved in ultrathin sections of glutaraldehyde-fixed, post-osmicated, Epon-embedded human renal needle biopsies using the indirect immunogold staining procedure. Extracellular Igs were identified in electron-dense deposits in subendothelial, intramembranous, subepithelial and mesangial locations in different cases of immune-complex-mediated glomerulonephritis. The excellent preservation of the ultrastructural morphology of the tissue sections made it possible to precisely correlate the presence and distribution of the antigens with those of the electron-dense deposits, which are the ultrastructural hallmarks of these diseases. Our post-embedding staining procedure which allows extracellular Igs to the accurately localized should be a very useful tool for immunomorphological investigations of glomerulonephritis.

Glomerulonephritis↗
PubMed1986

T-cell subsets in sarcoidosis: an immunocytochemical investigation of blood, bronchoalveolar lavage fluid, and prescalenic lymph nodes from eight patients.

T-lymphocyte subsets in peripheral blood, bronchoalveolar lavage fluid, and prescalenic lymph nodes from eight patients with sarcoidosis were evaluated with monoclonal antibodies. Both in lung and lymph nodes significant increases in helper T cells were demonstrated, except in patients with stage III pulmonary disease or with unaffected lymph nodes. A good statistical correlation was observed between the activity of the disease (expressed by an increased ratio of helper to suppressor/cytotoxic T cells) in bronchoalveolar fluid and in lymph node cell suspensions from each patient. A three-step immunoperoxidase staining reaction, performed on lymph node frozen sections, showed a prevalence of helper T cells both inside and around the granulomas. These findings confirm that sarcoidosis is characterized by increased activity of cell-mediated immunity in its different localizations.

Adult↗
PubMed1986

Ultrastructural immunolabeling in the diagnosis of light-chain-related renal disease.

Renal tissue from eight patients with light-chain deposition disease (LCDD) was immunolabeled for electron microscopy by a postembedding indirect immunogold staining procedure, using anti-kappa and anti-lambda antibodies. This technique provided an exact immunomorphological method to confirm the presence of monotypical light chains in glomeruli, tubules, and vessels. In two cases, it served to prove monotypical light-chain deposition which was not clear upon examination of sections stained for kappa and lambda light chains at the light microscopic level, using PAP or immunofluorescence methods. Three cases of amyloid nephropathy, in which the amyloid deposits stained for monospecific light chains and were immunolabeled ultrastructurally, are also described. LCDD manifests with a variety of morphological patterns in the kidney and the pathological definition of this entity has been difficult. Ultrastructural immunolabeling is a useful method to supplement existing techniques in the diagnosis of LCDD and related conditions. One outstanding feature of the postembedding technique is the ability to examine fixed and preserved renal tissue for the presence of light chains on a retrospective basis.

Adult↗
PubMed1986

Blood group substance, CEA, and lectins in ovarian tumors.

The presence of the blood group substances A, B, AB, Lea, and Leb and of CEA was demonstrated by peroxidase-antiperoxidase or fluorescein immunohistochemistry in histological sections of normal ovarian tissue and ovarian tumors of varying differentiation. In surface cells of normal ovaries and of benign tumors, blood group substances (BGS) were found in patterns corresponding to the serum blood group type of the patients. BGS were localized exclusively at the apical border of normal cells. CEA was almost always absent. In borderline lesions the presence of BGS was reduced by approximately 13%. The polar differentiation was often lost, and the BGS were unevenly distributed in the cytoplasm. The percentage of CEA-specific staining increased from less than 5% in normal tissue and benign tumors to 15% in mucinous and 10% in serous borderline tumors. Malignant tumors contained altered distribution patterns of BGS and CEA. In contrast to normal ovarian epithelia, BGS positivity was diminished distinctly; the decrease was particularly evident for Leb presence by reduction from 75 to 10%. CEA was observed in nearly 50% of the carcinomas (more often in mucinous than in serous carcinomas). Our study revealed that expression of blood group antigens was related to benign lesions, whereas its loss was associated with a greater malignant potential. Inverse correlations were found for CEA. Thus, immunohistological determination of these marker substances may be applied to tumor prognosis.

Blood Group Antigens↗
PubMed1985

Vasoactive intestinal polypeptide-, somatostatin-, and calcitonin-producing adrenal pheochromocytoma associated with the watery diarrhea (WDHH) syndrome. First case report with immunohistochemical findings.

A 30-year-old man presenting with watery diarrhea, hypokalemia, and hypochlorhydria (Verner-Morrison syndrome, WDHH syndrome) had raised plasma levels of vasoactive intestinal polypeptide (VIP), somatostatin (SRIF), calcitonin, and gastrin, as well as high urinary excretion of vanillylmandelic acid. A right adrenal pheochromocytoma was found and excised. The neoplastic cell population was immunohistochemically shown to contain VIP, SRIF, and calcitonin. Gross, histologic, and immunohistochemical evaluation of the pancreas revealed no abnormalities, whereas a marked hyperplasia of the gastrin-producing cells of the gastric antral mucosa was demonstrated. Postoperatively, the patient recovered from his symptoms and the plasma hormone levels returned to normal values. The clinical and histogenetic implications of this most unusual tumor of neural crest derivatives are discussed.

Adenoma, Islet Cell↗
PubMed1985

Posterior polymorphous dystrophy of the cornea. An ultrastructural study.

A corneal button excised from a 2-month-old infant with congenital posterior polymorphous dystrophy of the cornea, a rare disease affecting Descemet's membrane and endothelium, was examined by electron microscopy. We observed irregularly arranged, sometimes multilayered cells with marked epithelial features, lining the posterior surface of the cornea in place of the endothelium, and Descemet's membrane with focal alterations sometimes involving all of its layers. We interpreted these abnormal cells as epithelial-like cells. As these findings were in a very young patient, which is unusual, we concluded that the onset of the disease may take place in the early period of intrauterine life, corresponding to the beginning of Descemet's membrane production.

Cornea↗
PubMed1985

Ultrastructural localization of intracellular immunoglobulins in Epon-embedded human lymph nodes. An immunoelectron microscopic investigation using the immunogold staining (IGS) and the avidin-biotin-peroxidase complex (ABC) methods.

The ultrastructural localization of intracellular immunoglobulins on ultrathin sections of glutaraldehyde-fixed, postosmicated, and Epon-embedded human lymph nodes has been achieved using such highly sensitive immunocytochemical techniques as immunogold staining and avidin-biotin-peroxidase complex. These immunoelectron microscopic techniques allow the identification of intracellular immunoglobulins without affecting the ultrastructural morphology of the tissue, since they do not require any pretreatment of the sections with proteolytic enzymes or deresinating agents. Therefore, immunoglobulins can be precisely localized in the cell organelles; structures whose morphology is well preserved. The availability of a reliable postembedding staining procedure for the ultrastructural localization of immunoglobulins is of definite value for investigations on human lymphoid tissue, both normal and pathological.

Avidin↗
PubMed1984

Immunoelectron microscopy of human renal biopsies: prerequisites and limitations.

The traditional diagnostic approach to immunologically mediated glomerulonephritis is based on the morphological (both in light and electron microscopy) and immunofluorescence examinations of different samples of the same renal biopsy. A major disadvantage of this composite procedure is represented by the inability to precisely correlate the immunocytochemical data with the presence and distribution of electron-dense deposits. Immunoelectron-microscopic techniques could therefore represent a more useful tool for immunomorphological investigations into these glomerulopathies. In order to overcome the significant limitations of preembedding staining procedures, we introduce two postembedding staining techniques (using peroxidase or colloidal gold as markers of the immunoreaction) which result in a precise immunolocalization of immunoglobulins in the dense deposits of glutaraldehyde-fixed, postosmicated and Epon-embedded renal biopsies, while adequately preserving the ultrastructural morphology of the tissue sections.

Biopsy↗
PubMed1983

Morphologic evaluation of the liver in hereditary angioedema patients on long-term treatment with androgen derivatives.

17 alpha-Alkylated androgens are highly effective in preventing attacks in HAE patients. These drugs, however, seem to be implicated in the development of cholestatic jaundice, peliosis hepatis, and liver tumors. In order to assess the risk-benefit balance of the long-term therapy with androgen derivatives, a follow-up investigation was performed in 13 HAE patients. The results of this study indicate that long-term treatment (15 to 47 mo) with low doses of danazol or stanozolol does not induce significant hepatic damage detectable by laboratory tests or liver biopsy. However, the limited number of patients, although in a rather long period of observation, still suggests a careful control and the use of minimal effective doses.

Adult↗
PubMed1982

Immunohistochemical localization of human immunoglobulins and lysozyme in epoxy-embedded lymph nodes: effect of different fixatives and of proteolytic digestion.

The postembedding immunoperoxidase staining technique for the localization of immunoglobulins (light and heavy chains) and of lysozyme has been successfully applied to epoxy-embedded human lymph nodes, after removal of the resin. Glutaraldehyde-containing fixatives appear to be suitable for the immunohistochemical localization of human immunoglobulins and lysozyme, provided that the masked antigenicity of these proteins is recovered by proteolytic digestion of the tissue sections using 0.4% pepsin or 0.1% trypsin. Nonglutaraldehyde-containing fixatives allow the immunolocalization of human immunoglobulins without any enzymatic pretreatment. This study shows that tissues routinely fixed in glutaraldehyde and embedded for ultrastructural investigations are actually suitable for immunohistochemical studies on human immunoglobulins and lysozyme.

Female↗
PubMed1980

A simplified procedure for the preparation of antibodies to serum fibronectin.

In the present paper we describe in detail a simple procedure for the preparation of monospecific antisera to human and mouse serum fibronectin. A similar procedure could also be used to prepare antibodies to fibronectin from other species. The procedure, based on the recently reported affinity of fibronectin for gelatin, essentially consists of two steps (1) Immunization of rabbits with fibronectin purified from serum by affinity chromatography using gelatin coupled to CNBr-activated Sepharose 4B. (2) Absorption of the antiserum obtained by an immunoabsorbent prepared using fibronectin-free serum proteins that remained after absorbing serum with gelatin-Sepharose. The antisera obtained were monospecific, as determined by immunoelectrophoresis and did not show any difference with respect to antisera prepared by different procedures.

Animals↗
PubMed1979

Characterization of IgD. II. Molecular forms of IgD in human B cells.

Endogenous and surface labeling techniques were used on human lymphoid cells to characterize intracytoplasmic, membrane and secreted IgD, IgD synthesized by lymphocytes and inserted into the cell membrane displayed a single molecular form with the same mobility in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) as the previously described slow migrating serum IgDl. Plasma cells produced and secreted IgDl and another IgD corresponding to the faster-moving serum IgD2. Conversion of one molecular form into the other was never observed, thus indicating that neither molecule is a precursor or a degradation product of the other.

Autoradiography↗