concanavalin-a has been researched along with Adenoma* in 13 studies
13 other study(ies) available for concanavalin-a and Adenoma
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Evidence for thyroid hormone as a positive regulator of serum thyrotropin bioactivity.
The regulation of TSH bioactivity in humans is not completely understood.. The aim of the study was to investigate the role of serum thyroid hormones in regulating the bioactivity of TSH.. We determined in vitro TSH bioactivity and glycosylation in nine patients (six females and three males, age 41.3 yr) with primary hypothyroidism before and after L-T(4) replacement, in 11 age- and sex-comparable controls (seven females and four males, age 37.6 yr), and in two thyroidectomized patients with TSH-secreting adenomas during and after L-T(4) withdrawal.. In vitro TSH bioactivity was measured by a sensitive and specific bioassay based on cAMP generation by Chinese hamster ovary cells transfected with human TSH receptor. TSH glycosylation was assessed by concanavalin A lectin and ricin column affinity chromatography.. In vitro TSH bioactivity in hypothyroid patients was low as compared with controls (0.48 +/- 0.1 vs. 1.1 +/- 0.2; P = 0.004) and increased during L-T(4) (0.48 +/- 0.1 vs. 0.8 +/- 0.1; P = 0.01). A strong significant correlation (r = +0.80; P = 0.004, Spearman) was observed between the absolute increments of serum TSH bioactivity and T(3) during L-T(4) replacement. The degree of sialylation was elevated in hypothyroid patients before treatment (47 +/- 2.4% vs. 29 +/- 4.3%; P = 0.002) and decreased significantly after L-T(4) (47 +/- 2.4% vs. 33 +/- 4.3%; P = 0.02). The mannose content of serum TSH in hypothyroid patients was similar to controls and did not change during L-T(4). In vitro TSH bioactivity also decreased in patients with TSH-secreting adenomas during L-T(4) withdrawal.. These data indicate that serum thyroid hormone level is a positive regulator of TSH bioactivity. Topics: Adenoma; Adult; Animals; CHO Cells; Chromatography, Affinity; Concanavalin A; Cricetinae; Cricetulus; Cyclic AMP; Female; Glycosylation; Hormone Replacement Therapy; Humans; Hypothyroidism; Immunoassay; Male; Mannose; Middle Aged; Neuraminidase; Receptors, Thyrotropin; Ricin; Thyroid Hormones; Thyroidectomy; Thyrotropin; Thyroxine; Transfection | 2007 |
Pyloric gland-type tubular adenoma superimposed on intraductal papillary mucinous tumor of the pancreas. Pyloric gland adenoma of the pancreas.
We report a rare case of pyloric gland-type tubular adenoma of the main pancreatic duct. It was a grossly visible polypoid nodule and was composed of closely packed pyloric-type glands. This adenoma was present within an intraductal papillary mucinous adenoma (IPMA). In this IPMA lesion, aggregations of pyloric-type glands were occasionally observed, and most of the cells including ductal lining cells expressed pyloric gland-type mucin. The IPMA of the present case showed more extensive pyloric gland metaplasia or differentiation than commonly noted in IPMAs. We consider this pyloric gland-type tubular adenoma to be derived from a selective growth of IPMA cells showing pyloric gland metaplasia. Topics: Adenoma; Aged; Antibodies, Monoclonal; Concanavalin A; DNA, Neoplasm; Exocrine Glands; Gallstones; Gastric Mucosa; Genes, ras; Humans; Immunohistochemistry; Male; Metaplasia; Mucins; Mutation; Neoplasms, Second Primary; Pancreatic Ducts; Pancreatic Neoplasms; Polymerase Chain Reaction | 2002 |
Candidiasis in interferon-gamma knockout (IFN-gamma-/-) mice.
Germ-free C57BL/6 x 129 interferon-gamma knockout (IFN-gamma(-/-)) mice and their immunocompetent (+/-, +/+) counterparts were colonized with a pure culture of Candida albicans to assess their natural susceptibility to mucosal and systemic candidiasis of endogenous origin. Colonization with a pure culture of C. albicans was not lethal for adult or neonatal IFN-gamma(-/-) gnotobiotic mice over the 15-week study. The IFN-gamma(-/-) mice were more susceptible to gastric (cardia-antrum section), anorectal, and acute systemic (intravenous challenge) candidiasis than immunocompetent controls, and some IFN-gamma(-/-) mice developed intestinal adenomas after colonization with C. albicans. The enhanced susceptibility of IFN-gamma(-/-) mice, compared with immunocompetent controls, may be associated with a poor proliferative response of spleen cells to C. albicans antigens and a T helper 2 (IgG1) serum antibody response to C. albicans antigens. Thus, IFN-gamma is important for murine resistance to gastric, anorectal, and acute systemic candidiasis. Topics: Adenoma; Administration, Oral; Animals; Antibodies, Fungal; Candidiasis; Cell Division; Concanavalin A; Disease Models, Animal; Disease Susceptibility; Female; Genotype; Germ-Free Life; Interferon-gamma; Intestinal Neoplasms; Lipopolysaccharides; Lymphocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens | 1998 |
Unique binding pattern to concanavalin A lectin of glycoprotein hormones alpha-subunit hypersecreted by non-functioning pituitary adenomas.
This study analyzed the structural differences of the carbohydrate chains of circulating free alpha-submit (alpha-SU) hypersecreted in various non-tumoral (primary hypothyroids, postmenopausal women, patients with chronic uremia, normal fetuses) and tumoral (gut carcinoids, TSH-, GH- and pure alpha-secreting pituitary adenomas) clinical conditions. Carbohydrate structures of free alpha-SU were investigated by means of lectin affinity chromatography using Concanavalin A (Con-A), which allows the separation of free alpha-SU in three different fractions (unbound = UB, weakly bound = WB and firmly bound = FB) depending on the nature and maturation of glycosylated chains. The concentrations of alpha-SU in serum and in Con-A fractions were measured by a sensitive and specific IRMA. Free alpha-SU hypersecreted from postmenopausal women, primary hypothyroids, and patients with chronic uremia showed similar binding patterns to Con-A, the percentage of UB fractions (UB: 44.5 +/- 1.9%, 39.5 +/- 3.8%, 48.2 +/- 5.6% respectively) being higher than both WB and FB fractions (WB: 33.2 +/- 1.4%, 30.7 +/- 4.6%, 28.5 +/- 2.1%; FB: 22.3 +/- 0.7%, 29.8 +/- 6.6%, 23.3 +/- 4.2% respectively). In normal fetuses the amount of UB fraction was very high (UB: 70.7 +/- 5.4%). Free alpha-SU from patients with TSH- and GH-secreting adenomas showed a binding pattern to Con-A significantly different from that observed in postmenopausal women taken as controls, the WB fractions being significantly higher (WB: 56.9 +/- 16.8% and 71 +/- 12.4% respectively, P < 0.001). A typical pattern of elution on Con-A, characterized by a prevalence of immature alpha-SU molecules eluted in the FB fraction, was found in patients with pure alpha-secreting adenomas. This chromatographic behavior was significantly different from that seen in the controls, as well as in other pituitary tumors and in gut carcinoids (FB: 41.8 +/- 5.0%, 22.3 +/- 0.7%, 16.8 +/- 6.6%, 10.6 +/- 2.0% respectively). Moreover, in these latter patients the pattern of free alpha-SU binding was exactly the opposite of that observed in pure alpha-secreting adenomas, with a prevalence of mature alpha-SU molecules (UB: 59.1 +/- 4.4 vs 18.3 +/- 7.2%). In conclusion, our data on Con-A affinity chromatography clearly demonstrate that carbohydrate branching of circulating free alpha-SU varies in patients with pituitary adenomas as compared with patients with gut carcinoids or other non-tumoral conditions. Moreover, the finding of a greater prop Topics: Adenoma; Adult; Carcinoid Tumor; Chromatography, Affinity; Concanavalin A; Fetus; Glycoconjugates; Glycoprotein Hormones, alpha Subunit; Humans; Hypothyroidism; Intestinal Neoplasms; Pituitary Neoplasms; Postmenopause; Protein Binding; Uremia | 1997 |
Preneoplastic and neoplastic lesions of rat hereditary renal cell tumors express markers of proximal and distal nephron.
Long-Evans (Eker) rats carry a mutation that predisposes them to develop spontaneous renal cell tumors of two morphologic patterns: solid chromophilic masses or cystic lesions lined by eosinophilic cells. Previous studies have suggested that these tumors arise from the proximal tubules. In the present study, lectin-binding characteristics and cytokeratin expression of various stages of hereditary rat renal epithelial neoplasia were examined to localize the portion of the nephron from which tumors arise. Lectin-binding histochemistry has been used as a marker of cell surface glycoprotein expression, thought to be important in the differentiation of benign from malignant epithelial lesions and in the determination of their cell of origin. The presence or absence of keratin intermediate filaments in the rat nephron has been used to identify nephron segments. The polyclonal antibody to high- and low-molecular-weight cytokeratin stained the cells of the collecting ducts but not the proximal or distal tubules. Binding to the proximal tubules by the lectins Conavalia ensiformis (Con A), Dolichas biflorus, Ricinus communis (RCA-1), and Triticum vulgare and to the distal tubules by Con A, RCA-1, Arachis hypogaea (PNA) with and without neuraminidase, and the antibody for cytokeratins was demonstrated. The lectin binding and cytokeratin staining patterns of rat hereditary renal cell carcinoma, adenoma and the preneoplastic lesions of atypical tubules and hyperplasias suggest that cystic adenomas arise from the distal nephron, principally the collecting duct, whereas the solid atypical tubules, hyperplasias, and adenomas arise from the proximal nephron, principally the proximal tubule. Topics: Adenoma; Animals; Biomarkers, Tumor; Carcinoma, Renal Cell; Concanavalin A; Histocytochemistry; Hyperplasia; Immunohistochemistry; Keratins; Kidney Neoplasms; Kidney Tubules, Distal; Kidney Tubules, Proximal; Lectins; Male; Plant Lectins; Precancerous Conditions; Rats; Rodent Diseases; Wheat Germ Agglutinins | 1995 |
Variable carbohydrate structures of circulating thyrotropin as studied by lectin affinity chromatography in different clinical conditions.
Carbohydrate structures of intrapituitary and circulating TSH were studied by Concanavalin-A (Con A) and ricin lectin chromatography under different clinical conditions. Con A permits the separation of molecules differing in the extent of their carbohydrate branching, whereas ricin gives an estimation of the degree of their sialylation. Intrapituitary TSH was more retained on Con A and less sialylated than circulating hormone, suggesting that carbohydrate chains of intrapituitary molecules are less mature than those present in the circulation. A greater proportion of TSH firmly bound to Con A, compared to control values, was found in sera from fetuses and patients with uremia, TSH-secreting adenomas, and central hypothyroidism. In primary hypothyroid patients, TSH binding to Con A was similar to that found in controls, but a greater percentage of sialylated forms was seen. In central hypothyroidism patients, TSH released in response to TRH was less sialylated. Interestingly, no sialylated TSH was found in normal fetuses. In conclusion, the present data show that both TSH carbohydrate branching and sialylation may vary in different clinical conditions. As some of the above clinical conditions are known to be accompanied by variations in the bioactivity of circulating TSH, the finding of changes in TSH carbohydrate structures further supports the view that glycosylation modulates the expression of TSH biological activity. Topics: Adenoma; Carbohydrates; Chromatography, Affinity; Concanavalin A; Female; Fetus; Humans; Hypothyroidism; Isoelectric Focusing; Male; Molecular Structure; Pituitary Gland; Pituitary Neoplasms; Pregnancy; Ricin; Thyrotropin; Uremia | 1993 |
Lectin histochemistry in adrenocortical hyperplasia and neoplasms with emphasis on carcinoma.
Lectin binding analysis of Con A, SBA, PNA, WGA, HPA, RCA-I, DBA, and UEA-I was performed in two cases of normal human adrenal gland, four cases of adrenocortical hyperplasia, six cases of adrenocortical adenoma, and seven cases of adrenocortical carcinoma to examine the differences of lectin binding properties. No lectins were bound specifically to adrenocortical cells. Binding of RCA-I was observed in some carcinoma cells focally but not in benign counterparts. With WGA and Con A, the cytoplasmic binding became apparent in the cells manifesting hypercorticism. In adrenocortical carcinoma, various WGA and Con A binding patterns were intermingled, but no specific patterns were identified. The focal nature of RCA-I binding, and no specific WGA and Con A binding properties in carcinoma, suggest that diagnosis of malignant neoplasm must still largely rely on clinical, hormonal, and structural criteria in adrenocortical neoplasms. Topics: Adenoma; Adolescent; Adrenal Cortex; Adrenal Cortex Neoplasms; Adult; Carcinoma; Child; Child, Preschool; Concanavalin A; Cushing Syndrome; Female; Histocytochemistry; Humans; Hyperplasia; Lectins; Male; Middle Aged; Plant Lectins; Wheat Germ Agglutinins | 1989 |
Lectin expression in neoplastic and non-neoplastic lesions of the rectum.
The expression of six lectins (Arachis hypogaea, B. simplicifolia I, concanavalin A, Dolichus biflorus, Triticum vulgaris, Lotus tetragonolobus) was studied in 24 adenocarcinomas, 24 adenomas, 20 metaplastic polyps, 17 specimens of mucosal prolapse (solitary ulcer syndrome) and 10 of normal mucosa, all taken from the rectum. Qualitative, quantitative and distributive differences in lectin expression were observed between adenocarcinoma and normal mucosa. These cancer-associated glycoprotein alterations were also observed, though to a lesser extent, in benign neoplastic and non-neoplastic lesions of the rectum. It appears therefore that the glycoprotein modifications associated with malignant transformation are not specific indicators of malignancy. It is suggested that the common denominator is a disturbance in the activities of enzymes, particularly the glycosyl-transferases and glycosidases, involved in the biosynthesis of glycoprotein. This disturbance can occur in situations where cells are less differentiated either through developmental immaturity, rapid cellular division or neoplastic de-differentiation. These changes are therefore more likely to reflect the state of differentiation rather than the malignant nature of the cells. It is shown that the greater the deviation of the lesion from normal the greater the glycoprotein alterations. The potential usefulness of lectin expressions as predictive indicators of biological behaviour of adenocarcinomas of the large bowel needs further studies. Topics: Adenocarcinoma; Adenoma; Arachis; Concanavalin A; Histocytochemistry; Humans; Intestinal Mucosa; Lectins; Plant Lectins; Polyps; Rectal Neoplasms; Rectum; Triticum | 1988 |
Concanavalin A and Lens culinaris agglutinin binding patterns in normal and neoplastic sebaceous epithelium.
Formalin-fixed, paraffin-embedded tissue sections of normal skin, sebaceous hyperplasia, nevus sebaceus, sebaceous adenoma, and sebaceous carcinoma were studied by means of biotinylated and FITC conjugated concanavalin A (Con A) and Lens culinaris agglutinin (LCA). At relatively high concentrations of these lectins, all cutaneous epithelial cells were stained. As the concentration of LCA was lowered, there was a corresponding decrease in the intensity of staining of all epithelial cells. With lowered concentrations of Con A, staining of sebaceous epithelium remained strongly positive, while staining of other epithelia decreased in a manner similar to that seen for LCA. These staining patterns were seen in normal and neoplastic tissues. Both Con A and LCA are known to bind to alpha-D-mannopyranosyl and alpha-D-glucopyranosyl residues of glycoproteins and glycolipids. The difference in staining of sebaceous epithelial cells by Con A and LCA suggests that the binding of these lectins is not determined strictly by the presence of alpha-D-mannopyranosyl or alpha-D-glucopyranosyl residues, but is modified by side-chain substitution on the monosaccharides and/or by the oligosaccharide which contains the particular monosaccharide. Whichever event is operative, a saccharide moiety is present on the surface of mature sebaceous cells which has a strong affinity for Con A. Topics: Adenocarcinoma; Adenoma; Concanavalin A; Epithelium; Histocytochemistry; Humans; Hyperplasia; Lectins; Nevus; Plant Lectins; Sebaceous Gland Neoplasms; Sebaceous Glands | 1986 |
Difference of lectin binding sites of secretory granules between normal pituitary and adenoma cells.
Electron-immunocytochemical staining with lectin (concanavalin A: Con A) binding sites analysis was applied to study secretory granules of human pituitary adenomas and surrounding normal pituitary tissue using post-embedded serial ultrathin sections. Twelve cases of human pituitary adenoma and three specimens of normal pituitary tissue surrounding adenomas were studied: the cases were operated on between 1982 and 1984. The tumors consisted of four prolactin (PRL)-, six growth hormone (GH)-, and two adrenocorticotropic hormone (ACTH)-producing adenomas. In parallel with the detection of Con A binding sites of secretory granules, their secreting hormones were characterized electron-microscopically with the immunocytochemical horseradish peroxidase (HRP) labeling using the avidin-biotin technique. The two cases of ACTH-producing adenomas showed either weak or negative reactions with Con A on secretory granules, while normal ACTH-producing pituitary cells showed strong reactions with Con A on every secretory granule observed. Large secretory granules of PRL- or GH-producing cells showed negative reactions with Con A both in the pituitary adenoma and normal pituitary, while some small granulated or sparsely granulated adenoma cells also showed strong reactions with Con A. The complexity of human pituitary adenomas is illustrated as well as the difference in biochemical structure of normal pituitary cells and pituitary adenoma cells secreting the same specific hormone. Topics: Adenoma; Adrenocorticotropic Hormone; Binding Sites; Concanavalin A; Cytoplasmic Granules; Growth Hormone; Histocytochemistry; Horseradish Peroxidase; Humans; Immunochemistry; Microscopy, Electron; Pituitary Gland; Pituitary Neoplasms; Prolactin; Reference Values | 1985 |
[Comparative studies on immunological property of thyroglobulins obtained from the thyroid tumor and the adjacent tissue].
The immunological properties of thyroglobulins (Tg) of individual patients, obtained from a thyroid tumor and its adjacent tissue were compared, using conventional or monoclonal antibodies against human Tg. The thyroid tumors studied were non-functioning thyroid carcinomas and functioning thyroid adenomas. In contrast to non-functioning tumors, Tg from the functioning tumors was generally iodinated at a level close to that of normal tissue, and Tg from the tissue adjacent to the tumors had a very low iodine content. The conventional antiserum and monoclonal antibodies, B2F, seemed to recognize the conformation of Tg, while C6G showed a high affinity to Tg even when unfolded or denatured. In most cases, Tg isolated from the tissue adjacent to a tumor showed a higher affinity to antibodies than Tgs of the tumor tissue, as determined by the inhibitional effect of these Tgs against the binding of standard Tg and antibody. Furthermore, the Tg of the adjacent tissue was immunologically different in nature from the standard Tg obtained from a normal thyroid gland. From these results, Tgs of tumor and the adjacent tissue in individual patients were heterogeneous in immunological property, regardless of iodine content. Topics: Adenocarcinoma; Adenoma; Antibodies, Monoclonal; Carcinoma, Papillary; Concanavalin A; Humans; Thyroglobulin; Thyroid Gland; Thyroid Neoplasms | 1985 |
Hydantoin immunosuppression and carcinogenesis.
The immunological response of mice submitted to hydantoin treatment was determined. Hydantoin reduced the absolute number of spleen cells in treated animals and did not modify spleen cells reactivity to concanavalin A, although the response to SRBC challenge, as measured by the Jerne plaque-forming cell technique, was significantly decreased. Following these findings, the influence of hydantoin on carcinogenesis was evaluated by using the model of urethane-induced lung adenomas in SWR mice. Treatment with hydantoin significantly reduced the incidence of the induced adenomas. We confirmed that hydantoin modifies the immune response of the host mainly by depressing its humoral function and we have shown that this effect was associated with an inhibitory effect on tumour induction. Topics: Adenoma; Animals; Concanavalin A; Female; Immune Adherence Reaction; Immunity; Immunosuppression Therapy; Lung Neoplasms; Lymphocyte Activation; Mice; Phenytoin; Spleen; Urethane | 1975 |
Increased incidence of urethane induced lung adenomata by autosensitized lymphocytes.
The present work investigates the influence of autosensitized lymphocytes on the carcinogenic response of the host. Urethane treated SWR mice received 6 fortnightly injections of lymphocytes sensitized in vitro against syngeneic fibroblasts. An increased incidence of lung adenomata was found in these mice compared with controls injected with unsensitized lymphoid cells or with lymphoid cells sensitized against unrelated transplantation antigens. Autosensitized lymphocytes also modified the response of host lymphoid cells to concanavalin A or to stimulation in a mixed lymphocyte culture assay. These results indicate that autoimmune lymphocytes may increase susceptibility of a host to the induction of tumours. Topics: Adenoma; Animals; Autoantibodies; Autoantigens; Concanavalin A; Female; Fibroblasts; Graft vs Host Reaction; Immunity; Lung Neoplasms; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Lymphocytes; Mice; Mice, Inbred BALB C; Mice, Inbred Strains; Neoplasms, Experimental; Spleen; T-Lymphocytes; Transplantation, Autologous; Tritium; Urethane | 1974 |