Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Rice H500 tumor is a transplantable nonmetastasizing testicular tumor of Fischer rats associated with hypercalcemia and increased urine cyclic adenosine monophosphate (AMP) excretion, features similar to those of the clinical syndrome of humoral hypercalcemia of malignancy. Tumor cells can be maintained in tissue culture; one million cells grown in culture reinoculated in Fischer rats reproduce the syndrome of tumor growth and lethal hypercalcemia. Infusion of concentrated, serum-free cell culture supernatant into parathyroidectomized rats produced an increase in urine cyclic AMP similar to that produced by an infusion of bovine parathyroid hormone. Light and electron microscopic appearance of the H500 tumor in vivo and in vitro is similar to previous descriptions of a hypercalcemia-associated rat testicular tumor believed to be of Leydig cell origin. Ultrastructural characteristics of microvilli, intracellular glandlike lumina, and cell-cell attachments, however, suggest an epithelial origin. Absence of smooth endoplasmic reticulum typical of steroid-secreting Leydig cells suggest these cells are not actively involved in steroid synthesis and secretion. The ultrastructure of this tumor is sufficiently different from that of normal Leydig cells that the cell of origin is unclear. Nonetheless, this tumor provides a useful model of hormonally mediated tumor-associated hypercalcemia.
 ...
PMID:Morphologic and functional studies of a rat hypercalcemia-associated testicular tumor maintained in cell culture. 300 12

The clinical and pathologic features, including immunohistochemistry and electron microscopy, of six cases of poorly differentiated carcinoma of the ovary (small cell carcinoma) are presented. These tumors occurred in six young patients ranging in age from 10 to 24 years. Two patients had hypercalcemia. All tumors were unilateral, and four patients had advanced stage disease at presentation. Histologic features included sheets, nests, and cords of cells in a fibrous stroma, focal microcysts, and a dimorphic population of small and large cells. Eosinophilic, hyaline globules occurred in five cases, intercellular basement membrane-like substance in two cases, and glycogen in all cases. Five of six cases stained strongly for cytokeratin and vimentin; intracytoplasmic laminin was identified in three cases; and three cases were believed to show faint positivity for alpha-1-antitrypsin. Stains for alpha-fetoprotein were negative. Ultrastructural examination of two cases showed granular material in dilated rough endoplasmic reticulum, intermediate filaments, intracytoplasmic dense globules, maculae adherens, and extracellular basement membrane-like material. All of the cases proved rapidly fatal despite various therapies, as did a histologically similar testicular tumor that was admixed with seminoma and teratoma. We interpret these findings to indicate that this ovarian cancer is most likely of germ cell origin, and it may be related to yolk sac tumor, although it is clearly distinct from the classical yolk sac tumor.
 ...
PMID:Poorly differentiated (small cell) carcinoma of the ovary in young women: evidence supporting a germ cell origin. 302 45

The binding and internalization of [125I]iodoepidermal growth factor (EGF) by bone cells of the rat was demonstrated in situ by quantitative radioautography. Specific binding sites were observed on a cell profile enriched in endocytic components, including lysosome-like structures, a rough endoplasmic reticulum-rich cell profile, and a cell profile that histologically resembles an undifferentiated precursor cell. By the criteria of gel filtration and precipitability by trichloroacetic acid, most of the bound [125I]iodo-EGF was considered intact. By morphological criteria none of the cell profiles that bound [125I]iodo-EGF corresponded to fully formed osteoclasts or osteoblasts. The endocytic cell was found in the epiphyseal plate between the invading capillary and the transverse and longitudinal cartilage septa as well as near osteoclasts in the zone of mixed spicules. The rough endoplasmic reticulum-rich cell was present in vacated chondrocyte lacunae of the epiphyseal plate close to the metaphysis, and the poorly differentiated cell was observed between the mixed spicules of the metaphysis. Similar cell types were also found in the alveolar bone surrounding the incisors. These cells may be the origin of established bone cell lines that harbor high concentrations of EGF receptors and may also be responsible for the humoral hypercalcemia in response to the reported actions of injected EGF or transforming growth factor-alpha as well as that of malignancy.
 ...
PMID:In vivo demonstration of cell types in bone that harbor epidermal growth factor receptors. 326 Aug 55

Adenocarcinomas derived from apocrine glands of the anal sac and associated with persistent hypercalcemia in dogs were composed of tumor cells with numerous profiles of rough endoplasmic reticulum, clusters of free ribosomes, and a prominent Golgi apparatus. Neoplastic cells contained microtubules, microfilaments, tonofibrils, and had two types of electron-dense granules. Large lysosomelike dense bodies ranged from 0.6 to 2.2 microns in diameter and had a poorly delineated limiting membrane. Small granules (150-400 nm in diameter) had a sharply delineated limiting membrane with a narrow submembranous space and a homogeneous dense core. These smaller granules usually were located near the apexes of neoplastic cells, whereas the larger granules were situated near the base of cells. Apocrine cells in glands of the anal sac from control dogs that were in the secretory phase were columnar and had large dilated profiles of rough endoplasmic reticulum. Membranes of the endoplasmic reticulum fused with the plasmalemma and appeared to secrete their product directly into the lumens of acini, characteristic of merocrine secretion. Apical blebs of electron-lucent cytoplasm pinched off from nonneoplastic aprocine cells and were released into glandular lumens. Similar electron-lucent cytoplasmic blebs were present at the apexes of tumor cells. Myoepithelial cells were present between the epithelial cells and basement membrane in normal apocrine glands and were absent in neoplasms derived from these glands. Identification of the contents of the secretory-like granules in tumor cells and characterization of the hypercalcemic factor in the plasma or tumor tissue from dogs with this syndrome will help explain the pathogenesis of hypercalcemia associated with malignancy in animals and man.
 ...
PMID:Ultrastructural evaluation of adenocarcinomas derived from apocrine glands of the anal sac associated with hypercalcemia in dogs. 720 Jul 29

Under hypercalcemia induced by calcium gluconate the degranulation of renomedullary interstitial cells accompanied with the increase in volume of the rough and smooth surfaced endoplasmic reticulum and enlargement of the Golgi apparatus were observed. The ultrastructural changes can be regarded as an expression of the increase of a synthetic and secretory activity of these cells. Because the changes of renomedullary cells observed in hypercalcemia induced by calcium gluconate are not really different from that observed in hypercalcemia induced by vitamin D3 (Roszkiewicz et al. 1979) it can suppose that these changes may be connected solely with a calcium serum elevation and that the renomedullary interstitial cells rather do not play any important role in vitamin D3 metabolism.
 ...
PMID:The ultrastructure of renomedullary interstitial cells in hypercalcemia induced by calcium gluconate. 725 Jun 52

The pathogenesis of acute pancreatitis is poorly understood, despite well-recognised precipitating factors. Current evidence suggests that the earliest abnormalities of acute pancreatitis arise within acinar cells, but the key intracellular trigger has yet to be identified. Within the pancreas, physiological concentrations of secretagogues bind to G-protein-linked cell-surface receptors on acinar cells, evoking short, oscillatory spikes of acinar cytosolic-free ionised calcium ([Ca2+]i), an ubiquitous intracellular messenger. Specific effects within acinar cells include initiation of enzyme release through the phosphorylation cascades of stimulus-secretion coupling. Low resting levels of [Ca2+]i are restored by Ca(2+)-ATPase, which pumps calcium into the endoplasmic reticulum and out of the cell. If high concentrations of [Ca2+]i persist, toxicity results, intracellular signalling is disrupted, and cell damage occurs. Sustained elevations in acinar [Ca2+]i result from exposure to high concentrations of secretagogues, high doses of which also induce acute pancreatitis. Similarly, sustained elevations of [Ca2+]i may result from ductal hypertension, alcohol, hypoxia, hypercalcaemia, hyperlipidaemia, viral infection, and various drugs--all factors known to precipitate acute pancreatitis. We suggest that these factors precipitate acute pancreatitis by causing either excessive release of acinar [Ca2+]i, or damage to the integrity of mechanisms that restore low resting levels of [Ca2+]i, and that the consequent calcium toxicity is the key trigger in the pathogenesis of acute pancreatitis.
 ...
PMID:Is an elevated concentration of acinar cytosolic free ionised calcium the trigger for acute pancreatitis? 747 53

Gallium is a group IIIa transition metal that lowers serum calcium by an unknown mechanism and has been utilized in the treatment of cancer-associated hypercalcemia. The purpose of this study was to histomorphometrically investigate the ultrastructural effects of gallium nitrate on osteoclasts and osteoblasts in trabecular bone of normal nude mice and nude mice with humoral hypercalcemia of malignancy. Two groups of normal nude mice (n = 7 and n = 8, respectively) and two groups of hypercalcemic nude mice (n = 9) bearing a serially transplantable canine adenocarcinoma (CAC-8) were treated with vehicle or gallium nitrate. Osteoclasts were hypertrophied in vehicle-treated tumor-bearing nude mice as compared with vehicle-treated nontumor-bearing nude mice. Osteoclasts from tumor-bearing nude mice treated with gallium nitrate were significantly decreased in size and had fewer intracytoplasmic vesicles as compared with osteoclasts from vehicle-treated tumor-bearing nude mice. Degenerate osteoclasts, characterized by pyknotic nuclei and increased cytoplasmic vacuolation, were observed in both groups of gallium-treated nude mice. Osteoblasts from vehicle-treated tumor-bearing nude mice were hypertrophied and had extensive lamellar arrays of rough endoplasmic reticulum as compared with osteoblasts from vehicle-treated nontumor-bearing nude mice. Osteoblasts in gallium-treated nude mice (tumor-bearing and nontumor-bearing) were small and flattened with poorly developed cytoplasmic organelles. This investigation demonstrated that osteoclasts and osteoblasts in nude mice treated with gallium nitrate had ultrastructural evidence of decreased metabolic and functional activity. The results suggest that gallium nitrate lowers serum calcium by inhibiting osteoclastic bone resorption.
 ...
PMID:Ultrastructural and histomorphometric evaluations of gallium nitrate on bone in nude mice bearing a canine adenocarcinoma (CAC-8) model of humoral hypercalcemia of malignancy. 772 96

The clinical and pathological features of 150 cases of ovarian small cell carcinoma of the hypercalcemic type are described. The patients ranged from 9 to 43 (average 23.9) years of age. The serum calcium level was known to be elevated in 49 of the 79 patients (62%) whose preoperative calcium levels were measured. Four of these patients had symptoms of hypercalcemia, and one of them had undergone neck exploration with negative results before the ovarian tumor was discovered. At laparotomy the tumor was unilateral in 148 cases (99%). Extraovarian spread was present in approximately half the cases. The tumors ranged from 6 to 26 (average 15.3) cm in greatest dimension. Microscopic examination disclosed various patterns, the most common of which was diffuse sheets of cells punctured by variable numbers of follicle-like spaces; the tumor cells also grew in nests, cords, clusters, and singly. The follicle-like spaces, which were present in 80% of the cases, contained fluid that was almost always eosinophilic and rarely basophilic. Glands or cysts lined by mucinous epithelial cells were present in 12% of the neoplasms. The neoplastic cells were typically small and round with hyperchromatic nuclei and brisk mitotic activity. Fifty percent of the tumors, however, also had a variable component of cells with moderate to abundant amounts of eosinophilic cytoplasm, which sometimes contained large hyaline globules and large nuclei that were typically paler and had more prominent nucleoli than the small cells. Immunohistochemical staining confirmed the epithelial nature of the tumors, as did electron microscopy, which characteristically showed abundant dilated rough endoplasmic reticulum. Five of seven tumors investigated by immunohistochemical staining for parathyroid hormone-related protein showed positive results. All 23 tumors examined by flow cytometry with interpretable results were diploid. Fourteen of 42 patients (33%) with stage IA disease for whom follow-up information is available remained well and free of disease 1-13 (average 5.7) years postsurgery; 23 died of their disease, usually within 2 years; and five had recurrences but were alive at last follow-up. Almost all the patients with tumors of a stage higher than IA died of disease, but one patient with stage IIB disease who received intensive chemotherapy and radiation therapy is alive and apparently free of disease at 7 years. Features in stage IA tumors that appeared to be associated with a more favorable outcome included an age > 30 years, a normal preoperative calcium determination, a tumor size < 10 cm, and an absence of large cells.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Small cell carcinoma of the ovary, hypercalcemic type. A clinicopathological analysis of 150 cases. 794 31

Immunohistochemical and ultrastructural investigations of thyroid C cells were conducted in male nude (athymic) mice bearing a serially transplantable canine adenocarcinoma (CAC-8) model of humoral hypercalcemia of malignancy following subcutaneous administration of gallium nitrate. The following four groups were investigated: 1) vehicle-treated non-tumor-bearing control mice; 2) non-tumor-bearing mice treated with gallium nitrate; 3) vehicle-treated hypercalcemic mice bearing CAC-8; and 4) CAC-8 tumor-bearing mice treated with gallium nitrate. Gallium nitrate-treated tumor-bearing mice had a significant decrease in serum calcium as compared with tumor-bearing controls. C cells of non-tumor-bearing mice stained intensely for calcitonin and calcitonin gene-related peptide and weakly for chromogranin A and neuron-specific enolase. In C cells of both vehicle- and gallium-treated tumor-bearing mice, immunoreactive staining was decreased for calcitonin, calcitonin gene-related peptide, and chromogranin A, whereas there was a moderate increase in staining for neuron-specific enolase. Ultrastructurally, thyroid C cells in hypercalcemic tumor-bearing control and gallium-treated mice were hypertrophic and markedly degranulated as compared with those of non-tumor-bearing controls. Hypertrophic C cells contained few mature secretory granules, a well-developed Golgi apparatus, and lamellar arrays of rough endoplasmic reticulum. There was no evidence of C-cell hyperplasia. Immunohistochemical and ultrastructural findings revealed that C cells in mice with cancer-associated hypercalcemia were primarily in the actively synthesizing phase of the secretory cycle and had diminished immunoreactivity for calcitonin, calcitonin gene-related peptide, and chromogranin A.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of humoral hypercalcemia of malignancy and gallium nitrate on thyroid C cells in nude mice: immunohistochemical and ultrastructural investigations. 805 30

Plasma cell leukemia is a rare disorder with poor prognosis. We present a case of non-secretory primary plasma cell leukemia (Bence-Jones kappa type), which was treated successfully by VEP-IFN-alpha therapy. A 82-year old man was admitted to Kanazawa Medical University in May 1991, because of emaciation and dehydration. Clinical findings showed decreased level of gamma-globulin (IgG, IgA and IgM were all decreased markedly), hypercalcemia, renal dysfunction and increased serum beta-2 microglobulin. The peripheral blood leukocyte count was 30,100/microliters with 64% plasma cells, and 80.4% plasma cells were also observed in the bone marrow. Only light chain-kappa was detected in plasma cells by an immunohistochemical staining method, but immunoelectrophoresis showed no M-bow either in serum or urine. Electron microscopy revealed typical plasma cells with prominently developed rough endoplasmic reticulum. From these results, the diagnosis of non-secretory primary plasma cell leukemia was established. He was treated with VEP-IFN-alpha regimen, and plasma cells decreased markedly in both peripheral blood and bone marrow. Serum immunoglobulin recovered to within the normal range. After 6 courses of VEP-IFN-alpha, complete remission was achieved and the remission was maintained until he died of an unrelated event, bronchial obstruction due to misswallowing, in April 1992.
 ...
PMID:[Successful VEP-IFN-alpha therapy in a case of non-secretory plasma cell leukemia (BJ-kappa type)]. 807 91


<< Previous 1 2 3 4 Next >>