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Biomedical subjects

C Capella

Publications and source records attributed to C Capella.

At least 109 records · Page 6Linked to original sources

Characterization of four main cell types in gastric cancer: foveolar, mucopeptic, intestinal columnar and goblet cells. An histopathologic, histochemical and ultrastructural study of "early" and "advanced" tumours.

Gastrectomy specimens of 148 gastric cancers, 40 of them being intramucosal or microinvasive, 27 penetrating the submucosa and 81 invading the muscularis propria, with or without involvement of the serosa and perigastric tissues, have been investigated with conventional histopathologic techniques, mucin histochemistry and electron microscopy to characterize the various lines of tumour cell differentiation and to correlate these with the histologic patterns of tumour growth. More or less differentiated intestinal columnar, intestinal goblet, gastric foveolar or mucopeptic cells were recognized in most tumours, of glandular, diffuse or mucoid type. Although simultaneous expression of more than one cell type into the same tumour occurred very frequently, intestinal columnar cells were more prominent in tubular adenocarcinomas, goblet cells (especially of colorectal type) in mucoid cancers, mucopeptic cells in diffuse cancers of invasive desmoplastic type and foveolar cells in diffuse cancers of intramucosal signet-ring cell type. In general, an increased tendency to foveolar cell differentiation and a reduced tendency to mucopeptic differentiation has been found in intramucosal cancers as compared to invasive cancers. It is concluded that the type of tumour cell differentiation, which might have some influence on the natural history of gastric cancer, is better related with more defined tumour subtypes than with the usually recognized glandular or diffuse patterns.

Gastric Mucosa↗

Electron immunocytochemical localization of pepsinogen I (PgI) in chief cells, mucous-neck cells and transitional mucous-neck/chief cells of the human fundic mucosa.

Specific PgI antibodies devoid of PgII cross reactivity have been applied to aldehyde-osmium fixed human, fundic-type, gastric mucosa investigated with the protein A-immunogold technique. PgI immunoreactivity has been detected in the homogeneous secretory granules of glandular chief cells, in bipartite granules of mucous-neck cells, in the granules of cells showing intermediate patterns and topography in between chief and mucous-neck cells (transitional cells), as well as in the granules of a few cells in the foveolar/mucous-neck boundary zone showing mixed foveolar/mucous-neck granule populations. The findings support progressive transformation of mucous-neck cells into chief cells.

Gastric Fundus↗

Gastric carcinoids and related endocrine growths.

A series of 30 gastric endocrine tumours has been revised in the light of available available cytologic and clinicopathologic information. Among 24 well differentiated endocrine tumours-16 with and 8 without chronic atrophic gastritis (CAG)-3 gastrin cell tumours have been distinguished from 21 argyrophil carcinoids, 15 of which showed light- and/or electronmicroscopy patterns of enterochromaffin-like (ECL) cell tumours, 2 of EC cell tumours and 1 of D1/P cell tumour. One case of mixed carcinoid/adenocarcinoma and 5 cases of endocrine carcinomas, 4 poorly and 1 moderately differentiated, were also identified. Achlorhydria, due to type A CAG or HCl-suppressing drugs, and bombesin hyperstimulation are among possible factors inducing G cell hyperfunction and/or hyperplasia. Hypergastrinaemia is among causative agents of argyrophil ECL cell hyperplasias and, possibly, of tumours of the oxynticopeptic mucosa, while chronic inflammation and gland atrophy with or without concomitant hypergastrinaemia are important factors in inducing both hyperplastic and tumour argyrophil growths in CAG mucosa.

Carcinoid Tumor↗

Growth hormone-releasing factor does not stimulate phosphoinositides breakdown in primary cultures of rat and human pituitary cells.

It has been reported that rat growth hormone releasing factor (rat GRF-43), similarly to the two human GRFs (GRF-40 and 44) stimulates adenylate cyclase activity in pituitary cells. Controversial findings have been presented by two different groups on the action of GRF on phosphoinositides (PI) metabolism, a phenomenon linked to Ca-- mediated intracellular mechanisms. In the work to be reported, we evaluated the accumulation of inositol phosphates induced by GRF exposure in primary cultures of rat and human pituitary cells. Addition of rat GRF-43 to rat pituitary cells at doses up to 1 microM had no effect on inositol phosphates accumulation, while already at a dose as low as 0.05 nM it increased growth hormone secretion in the incubation medium significantly. In the same cell system, TRH, a known activator of PI breakdown, significantly increased [3H]inositol phosphates. In primary cultures of human somatotrophs from acromegalic subjects as in rats, addition of hpGRF-40 and also of TRH did not elicit any modification in the accumulation of [3H]inositol phosphates. Consistent with in vivo findings, both peptides induced a significant release of GH in the medium. Our results show that the GH releasing effect of GRF does not involve the hydrolysis of phosphatidylinositol in normal rat as well as in tumoral human somatotrophs. In addition it appears that the anomalous response of TRH on adenomatous cells from acromegalic patients is differently mediated in respect to the action of the tripeptide on normal lactotrophs and thyrotrophs.

Acromegaly↗

Amphicrine cells, dysplasias, and neoplasias.

The existence of epithelial cells displaying synchronous features of exocrine and endocrine differentiation has been well established. Sporadic descriptions of neoplasms comprising or including such cells have also been recorded. The authors investigated eight carcinomas (lung, two; stomach, two; colon, one; appendix, one; esophagus, one; and pancreas, one). By conventional light microscopy, all eight neoplasms appeared as moderately to well-differentiated adenocarcinomas. Mucosubstance stains showed positive material within well-defined lumina and as intracytoplasmic droplets. Argyrophil stains were positive in seven of the eight neoplasms. The esophageal tumor was a predominantly solid carcinoma; it compromised small to intermediate cells with focal mucosubstance positivity and squamous pearls. By electron microscopy, all these carcinomas including cells displaying variable complements of neurosecretory granules, which were concentrated in the basal pole or in cytoplasmic processes. The granule population was often heterogeneous. The pancreatic carcinoma also showed typical zymogen granules. In all cases, many of the neoplastic cells had true lumina or intracytoplasmic lumina, as well as arrays of filaments; secretory granules were also observed in cells with true or intracytoplasmic lumina. Immunohistochemical studies revealed in all cases either serotonin or one of a spectrum of neuropeptides. Five tumors contained more than one immunoreactive material. The authors conclude that synchronous exocrine and endocrine differentiation may be comparatively frequent in a spectrum of tumors that may be properly termed "amphicrine" carcinomas. This demonstrable heterogeneity of malignant cell populations, however variably expressed, may prove to have considerable significance in the diagnosis and management of these neoplasms.

Adenocarcinoma↗

Ultrastructural localization of cholecystokinin in endocrine cells of the dog duodenum by the immunogold technique.

Cholecystokinin (CCK) has been localized by the immunogold technique in a type of endocrine cell of the dog duodenum characterized by small (166 +/- 38 nm) secretory granules with fairly dense, homogeneous core separated from its enveloping membrane by a thin clear space. The CCK cell is immunocytochemically distinct and cytologically different from other types of endocrine cells, as the secretin, GIP and motilin cells, already identified in the dog duodenum.

Animals↗

Tryptophyllin-like immunoreactivity in rat adenohypophysis.

A new amphibian peptide family has been isolated from the skin of a South American frog Phyllomedusa rhodei and named Tryptophyllins (TPH) because of their content in tryptophyl residue. Using an antiserum against one of these peptides, namely the pentapeptide Met-5-TPH-5-amide (PHE-PRO-PRO-TRP-MET-NH2), we observed the presence of a set of immunoreactive cells in rat adenohypophysis. These cells were far more numerous in pregnant than in normal male and non-pregnant female rats. Dual immunostainings demonstrated that, with some exceptions, almost all the TPH-like immunoreactive cells were gonadotrophs. At electron microscope both types of gonadotroph cells displayed immunoreactivity and the gold particles strongly labelled both types of granules. The Aa. advance the hypothesis that, besides the hormones themselves, the secretory granules might contain some TPH-like sequence.

Animals↗

Glucagon- and PP-related peptides of intestinal L cells and pancreatic/gastric A or PP cells. Possible interrelationships of peptides and cells during evolution, fetal development and tumor growth.

The immunohistochemical detection of six distinct sequences of proglucagon and its derivatives (GRPP, glicentin, glucagon-37, glucagon-29, GLP1, GLP2 and MPGF) in both intestinal L cells and pancreatic or gastric A cells of some mammals (dog, man, guinea pig) confirms that the two cell types produce the same proglucagon molecule, although the final step of its post-translational processing differs in the two cells. Immunohistochemical and ultrastructural patterns of glucagon/glicentin cells in the pancreas of lower vertebrates and early human fetuses, as well as tumor cell studies, suggest an evolution of gastropancreatic A cells from L cells. On the contrary, the PP-related peptide PYY of intestinal L cells, and PP with its C-terminal icosapeptide extension of pancreatic PP cells, likely originate from different prohormones. Although intermediate patterns of peptide expression can be observed, including some F-type PP cells of the dog pancreas (uncinate process) and pyloric mucosa showing PYY immunoreactivity or rare PYY and/or HPP immunoreactive cells of the human rectum lacking glicentin reactivity, no obvious relationship can be established between L cells and pancreatic (F-type) PP cells. However, some evolutionary, embryogenetic and oncogenetic link may exist between L cells and human D1-type PP cells, a minor population of PP cells scattered in the pancreatic tissue of dorsal pouch origin and a major fraction of tumor PP cells.

Animals↗

Ultrastructural localization of gastric inhibitory polypeptide (GIP) in a well characterized endocrine cell of canine duodenal mucosa.

The polypeptide hormone GIP has been localized ultrastructurally by using specific, monoclonal GIP antibodies and an immunogold technique on aldehyde-osmium fixed specimens of dog duodenal mucosa. A single type of cell showing round, homogeneous, fairly osmiophilic granules with closely applied membrane and a mean size of 188 nm +/- 34 SD has been identified as the GIP cell.

Animals↗

Ultrastructural localization of secretin in endocrine cells of the dog duodenum by the immunogold technique. Comparison with ultrastructurally characterized S cells of various mammals.

Secretin has been localized by the immunogold technique in endocrine cells of the dog duodenum--previously described as "K cells"--characterized by secretory granules with double structure consisting of a secretin-containing osmiophilic core surrounded by an argyrophil halo. Granules resembling those of dog secretin cells were also found in some ultrastructurally characterized S cells of the cat, pig, rat and rabbit duodenum, thus confirming in these species the identification of S cells with secretin cells. Conversely, the cells previously described as "S cells" in the dog lacked secretin immunoreactivity.

Animals↗

Ultrastructural localization of motilin in endocrine cells of human and dog intestine by the immunogold technique.

Motilin-immunoreactivity has been localized by two electron immunocytochemical techniques, using gold-labelled protein A or IgG as second layer, in a specific type of endocrine cell scattered in the epithelium of human and canine upper small intestine. The motilin (M) cell is characterized by relatively small (180 nm in man; 200 nm in the dog), solid granules with homogeneous core and closely applied membrane, round in man, round to irregularly-shaped in the dog. Perinuclear microfilaments are prominent in human motilin cells.

Animals↗

Primary oat cell carcinoma of the kidney.

A malignant renal neoplasm with all the morphologic attributes of oat cell (small cell, neuroendocrine) carcinoma is presented. It metastasized widely to regional lymph nodes and resulted in the death of the patient. Ultrastructurally, the tumor contained dense-core endocrine-type secretory granules. It had a cell component which was argyrophilic and which gave a positive immunocytochemical reaction for calcitonin. To the best of our knowledge, this is the first documentation of this tumor type in the kidney.

Aged↗

Gastric parietal cell carcinoma--a newly recognized entity: light microscopic and ultrastructural features.

Three cases of gastric parietal cell carcinoma are described. Tumour cells are round to polygonal, with abundant eosinophilic, granular cytoplasm reactive with phosphotungstic acid haematoxylin and Luxol Fast Blue. Ultrastructurally the tumour cells are characterized by abundant mitochondria, tubulovesicles, intracellular canaliculi and intercellular lamina filled with undulated microvilli.

Aged↗

Neoplastic cells containing lysozyme in gastric carcinomas.

A case of gastric carcinoma mostly composed of cells with histological, immunohistochemical and ultrastructural features of Paneth cells prompted a comparative investigation of the occurrence of similar cells in gastric, colorectal and mammary carcinomas. Cells containing lysozyme were demonstrated by the immunoperoxidase-PAP technique in 34.9% of 83 gastric carcinomas. They were found in 38% of intestinal-type and in 30% of diffuse-type tumours. Paneth-type granules were demonstrated ultrastructurally in 4 of 7 carcinomas in which lysozyme had been demonstrated immunohistochemically. No lysozyme was demonstrated in a series of 30 breast carcinomas and in only 1 of 27 cases of colorectal neoplasm. The possibility of using lysozyme as a marker for some carcinomas of gastric origin is considered.

Adult↗

The contribution of immunohistochemistry to the diagnosis of neuroendocrine tumors.

The use of specific secretory products, hormones, and neuroregulators as diagnostic tools for neuroendocrine tumors is illustrated. Results of extensive immunohistochemical and cytologic investigations are discussed in the light of other pathologic and clinical findings to serve as a basis for tumor classification and as a help in prognostic evaluation. Endocrine tumors of the pancreas, gut, lung and urogenital tract are dealt in some detail.

Gastrointestinal Neoplasms↗

Morphologic patterns and diagnostic criteria of VIP-producing endocrine tumors. A histologic, histochemical, ultrastructural, and biochemical study of 32 cases.

Thirty-two tumors (31 pancreatic and one jejunal) all associated with severe watery diarrhea, increased VIP levels in blood and most with hypokalemia, were investigated. The VIP content of tumor tissue ranged from 23 to 15,000 pmol/g. VIP immunoreactive cells were detected histochemically in 24 of 28 tumors investigated, PP immunoreactive cells in 11 of 28 tumors, hCG (alpha chain) immunoreactive cells in 12 of 25 tumors, and neuron specific enolase (NSE) immunoreactive cells in 24 of 26 tumors (the 2 negative results were due to inadequate fixation). All cases showed light microscopic features of epithelial endocrine tumors. Electron microscopy demonstrated a prevalence of agranular, poorly granulated and a minority of well granulated cells. Most secretory granules were round, small (150+/- 30 nm diameter) and of moderate electron density, resembling those of the so-called D1 cells. By electron immunocytochemistry, PP was directly localized in a subpopulation of relatively larger granules (154 +/- 22 nm core diameter) showing closely applied membranes. VIP-storing granules, directly identified only in the jejunal tumor, appear to correspond to a subpopulation of slightly smaller P-type granules (126 +/- 37 nm core diameter) showing a narrow, clear halo. The origin, behavior, and diagnostic criteria of VIPomas are discussed.

Adult↗

Pancreatic polypeptide (PP) cells in the PP-rich lobe of the human pancreas are identified ultrastructurally and immunocytochemically as F cells.

The ultrastructure of immunohistochemically identified PP cells has been investigated by applying the serial semithin/thin section technique to the human pancreas, with special reference to the posterior part of the head, reputed to originate from the ventral primordium. PP cells of this area differ from those already identified in the rest of the pancreas and correspond to a cell, not yet described in the human pancreas, characterized by larger granules of very variable shape and structure. Such granules resemble those of so-called "F cells", i.e. the PP cells of dog uncinate process and cat duodenal lobe, also coming from the ventral primordium. Thus, human "ventral lobe" PP cells have peculiar potentialities which are expressed in distinctive structural patterns of presently unknown functional meaning.

Fetus↗