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Biomedical subjects

A Sapino

Publications and source records attributed to A Sapino.

86 records · Page 5Linked to original sources

Specific demonstration of myoepithelial cells by anti-alpha smooth muscle actin antibody.

The myoepithelial cells of the sweat, mammary, tracheobronchial, and salivary glands are specifically identified by monoclonal antibody alpha-SM-1, which recognizes alpha smooth muscle actin and not the other actin isoforms. Basal or "reserve" cells in the stratified epithelia and excretory ducts of the salivary glands are negative, as well as all other epithelial cells in various organs. The reaction can be performed in routinely fixed and embedded tissues and is of practical interest in diagnostic histopathology. In immunoelectron cytochemistry, alpha-SM-1 antibody binds to the microfilament bundles in myoepithelial cells of the breast, but does not stain luminal cells and occasional basally located epithelial cells. These basal cells are morphologically and immunocytochemically distinct from the myoepithelial cells, and their nature and significance remain to be clarified.

Actins↗

Effects of estrogens on the testis of transsexuals: a pathological and immunocytochemical study.

Testes from five male-to-female transsexuals removed during sex-reversal surgery after administration of estrogens were studied histologically and with immunoperoxidase procedures to locate estrogen receptors (ER) and related antigens. Atrophy of the seminiferous tubules was observed in all cases; its degree, and a marked decrease in Leydig cells, correlated with low plasma gonadotropin levels (rather than with the duration of treatment). In all cases, the rete testis appeared hyperplastic and the other components (efferent ductules, epididymus) well preserved. The efferent ductules proved to be the only structure where ER can be located by the ER-ICA procedure, whereas staining for the p 29 ER-associated antigen is strongly positive both here and in the rete testis. The immunocytochemical data, in parallel with the observed biological effects, indicate that the rete testis and the efferent ductules and, to a minor degree, the epididymus and Leydig cells are the main direct targets of estrogens in the human testis.

Adult↗

Endocrine markers in argyrophilic carcinomas of the breast.

Argyrophilia in breast carcinomas is of uncertain significance. We tested a series of 20 cases of Grimelius-positive carcinomas with immunocytochemical markers of endocrine or exocrine differentiation. Fifty per cent of these tumors were positive, in a variable percentage of the neoplastic cells, with monoclonal antibodies against chromogranin, a specific marker of neuroendocrine differentiation. All cases were positive for neuron-specific enolase, but the significance and specificity of the reaction remain doubtful. The apparent positivity for alpha-lactalbumin, as found also by Clayton and coworkers, was found to be related to a contaminant, which is in fact also an endocrine marker. As with other types of breast carcinoma, all our cases were positive for epithelial membrane antigen, evidence that argyrophilic breast carcinomas, and specifically the chromogranin-positive subgroup, should be interpreted as endocrine neoplasms displaying multidirectional differentiation.

Aged↗

Estrogen- and tamoxifen-induced rearrangement of cytoskeletal and adhesion structures in breast cancer MCF-7 cells.

The cytoskeleton, the shape, and the adhesion complexes of MCF-7 breast carcinoma cells have been studied by fluorescence, phase contrast, and interference reflection microscopy. Cells have been grown in media containing different concentrations of estrogen and with or without the addition of the antiestrogen tamoxifen. The pattern of actin microfilaments and keratin intermediate filaments (tonofilaments) and the distribution of adhesion areas change as a function of the estrogen concentration. When cells are cultured in estrogen-deprived medium, they appear roundish and flattened and adhere firmly to the substratum, with multiple vinculin-positive adhesion plaques at their ventral surface. Upon stimulation with estrogen, these cells display pseudopodial cytoplasmic protrusions and ruffling membranes; in interference reflection microscopy the adhesion areas are mostly localized in these projections. A rearrangement of microfilaments and of tonofilaments in the cell projections and the formation of a dense network of keratin fibers takes place. Tamoxifen affects cellular shape and cytoskeletal arrangement in a way similar to that induced by estrogen. An effect of estrogen-receptor stimulation on the adhesion structures and on the rearrangement of intermediate and actin filaments (and accordingly of the shape and internal structure of breast cancer cells) can be suggested. Such an effect might be direct or mediated through unknown mechanisms; it seems, however, to be independent of the well known estrogenic effect on cell proliferation.

Actins↗

Chromogranin-reactive endocrine cells in argyrophilic carcinomas ("carcinoids") and normal tissue of the breast.

Breast carcinomas, either positive or negative with the Grimelius' silver procedure, benign fibroadenomas, duct papillomas, and areas of histologically normal breast tissue were tested immunocytochemically with the mouse monoclonal antibody LK2H10 directed against human chromogranin. This is regarded as a general stain for polypeptide-hormone-producing cells and tumors. In 3 of the 9 cases of argyrophilic carcinoma, but in none of 12 ductal infiltrating carcinomas, chromogranin-positive cells were found: the number of reactive cells was very low in 1 case, while in the other 2 carcinomas about 50% of the argyrophilic cells appeared stained. In areas of histologically normal breast tissue, rare argyrophilic chromogranin-positive cells were detected. This study is the first reported evidence concerning the presence of endocrinelike cells probably belonging to the diffuse neuroendocrine system in the normal mammary parenchyma. Our data are consistent with the endocrine nature of at least some of the breast argyrophilic carcinomas.

Adult↗

Estrogen and tamoxifen induced cytoskeletal changes in breast cancer cells.

The MCF-7 and CG-5 breast carcinoma cell lines were grown under different concentrations of estrogen and with or without the addition of tamoxifen to the media. Similar results were obtained with either cell lines. Cells cultured in estrogen-supplemented medium showed a marked change of the cell shape with the appearance of long projections sprouting from the cell body, adhesion areas being localized at the tips of these projections. A redistribution of bundles of prekeratin and actin fibres could be visualized by appropriate immuno-cytochemical procedures. Vimentin intermediate filaments and microtubules did not appear significantly modified by hormone conditioning. Tamoxifen treatment resulted in structural and cytoskeletal changes similar to those observed in estrogen stimulated cells. These data indicate that the shape and the cytoskeletal architecture of breast cancer cells can be conditioned by hormone treatment.

Breast Neoplasms↗

Binding of antibodies against human prealbumin to intestinal and bronchial carcinoids and to pancreatic endocrine tumours.

Antibodies against human prealbumin (HPA) give a strong immunoperoxidase staining of the A (glucagon) pancreatic cells and of glucagon-, insulin- and gastrin-producing pancreatic tumours. The majority of intestinal and bronchial carcinoids are also reactive. The staining may be related to presence in the C-terminal sequence of HPA of determinants in common with polypeptide (pro-) hormones.

Adenoma, Islet Cell↗

Effects of long-term administration of high doses of medroxyprogesterone acetate on hormone receptors and target organs in the female rat.

The changes in oestrogen, progesterone and prolactin receptor levels in target organs, and the macroscopic and microscopic modifications of uterus, ovary, adrenal and pituitary gland induced by long-term administration of high doses of medroxyprogesterone acetate (MPA) were investigated in female rats. Medroxyprogesterone acetate was injected i.m. for 30 days at daily doses of 7.5, 15 and 75 mg/kg. Oestrogen and/or progesterone-binding capacities were remarkably reduced at all doses of MPA used both in the uterus and pituitary gland. Furthermore, MPA caused a very evident reduction in the weight of pituitary glands, ovaries, adrenals and uterus. In all MPA-treated rats corpora lutea were absent from the ovaries, whereas the adrenals showed a significant reduction in the thickness of the cortex. In accordance with this, there was no evidence of ACTH-producing cells in the pituitary glands. Prolactin-producing cells were also absent, while GH-producing cells were present. Serum prolactin levels were significantly reduced at all doses of MPA used. A dramatic reduction of prolactin receptor concentrations was observed in the liver and the ovaries of MPA-treated rats. The results suggest that MPA acts as an antioestrogenic drug both by reducing the number of oestrogen receptors in target tissues and by changing the structure (and perhaps the function) of those organs (pituitary glands, ovaries and adrenals) which are, directly or indirectly, a source of oestrogens. The decreased synthesis of prolactin and the reduction of the number of prolactin receptors (which, on the contrary, are both increased by oestrogens) might be considered as additional antioestrogenic effects of MPA.

Adrenal Glands↗

Apocrine cells in a fine needle aspirate of gynecomastia. A case report.

BACKGROUND: Apocrine cells are a common finding in female mammary cysts, while only rare cases of apocrine metaplasia in gynecomastia have been found in surgical specimens. CASE: A 65-year-old male presented with painful, monolateral gynecomastia. Fine needle aspiration biopsy showed sheets of large, eosinophilic epithelial cells. On immunocytochemistry these cells were positive for apocrine marker GCDFP-15. The patient had ischemic heart disease and was under treatment with spironolactone. CONCLUSION: Apocrine cysts in gynecomastia are rare histologic findings, and this is the first case diagnosed by fine needle aspiration. The finding of apocrine cells confirms the nonneoplastic nature of the lesion, avoiding surgical excision.

Aged↗

[Tumor samples as a tool for large-scale monitoring of antigen-specific lymphocytes in gastric and colorectal neoplasms].

The characterization of tumor-associated antigens has enabled to direct the host immune response towards the autologous tumor through appropriate loading and presentation of the antigen. In vivo conditions that generate large numbers of tumor antigens would be an important step in vaccine strategies. In this study we have therefore tested the ability of freshly isolated gastric and colorectal cancer cells to induce a specific anti-tumor response in autologous T lymphocytes. Because dendritic cells (DC) are critically involved in both initiating and boosting host immune responses, they have been used to present apoptotic bodies generated by irradiated tumor cells. Results show that these native antigens stimulate T cytotoxic response against tumor, but not peritumor normal tissues. Induction of IFN-gamma secreting cell activity, which is a standard readout in current cancer vaccine protocols, was also demonstrated by Elispot single-cells assay. These data show the antigenicity of gastric and colorectal tumor cells and open new perspectives in immunotherapy.

Adenocarcinoma↗

Oxytocin receptor within the breast: biological function and distribution.

In the present work, first we reviewed and completed our previous experiments on the antiproliferative effect of oxytocin (OT) in breast cancer cell lines. In vitro, OT 10 nM and 100 nM inhibited cell proliferation of MDA-MB231 (human breast carcinoma) and TS/A (mouse mammary carcinoma) cell lines. In vivo, OT significantly reduced the growth of TS/A mammary tumors. Both effects are mediated by specific receptors (OTR) distributed on cell surface. Second, using immunohistochemistry and RT-PCR we detected OTR and OTR mRNA in normal and pathological breast tissue. There is no correlation among OTR presence in breast carcinomas and the age of patients, tumor stage, estrogen receptor positivity, oncogene expression and proliferation rate of the same tumor. On the contrary, progesterone and OTR expression are correlated. These data confirm our previous evidence of a role of OT and OTR in normal and neoplastic breast cells.

Adult↗