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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of so-called mesothelioma of the atrioventricular node is presented. Controversy exists as to whether this lesion is of mesodermal or endodermal origin. The light and electron microscopic morphologic characteristics in this case were identical to those reported previously. The glandular component produced mucin that resisted digestion with both hyaluronidase and diastase; this staining pattern is characteristic of endodermal rather than of mesodermal tissue. Immunohistochemical methods demonstrated abundant carcinoembryonic antigen (CEA) in the cytoplasm of the cells composing the lesion. The presence of CEA strongly argues for an endodermal origin, since this antigen characterizes tissue derived from endoderm and is generally absent from mesoderm. The lesion probably represents endodermal foregut tissue that is displaced during embryogenesis. As such, it is not a true neoplasm. It is proposed that this lesion be designated "congenital endodermal heterotopia of the atrioventricular node."
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PMID:Congenital endodermal heterotopia of the atrioventricular node: evidence for the endodermal origin of so-called mesotheliomas of the atrioventricular node. 638 61

The expression and core protein structure of two proteoglycans, the major cartilage proteoglycan isolated from a rat chondrosarcoma and a small molecular weight chondroitin sulfate proteoglycan isolated from a rat yolk sac tumor, have been compared. The cartilage proteoglycan was not detectable in the cartilage tissue of cartilage matrix deficient (cmd/cmd) neonatal mice by immunofluorescence, but the cmd cartilage did react with antibodies against the core protein of the yolk sac tumor proteoglycan. Radioimmunoassays showed that the core proteins of these proteoglycans are not cross-reactive with each other. Analysis of the core proteins by sodium dodecyl sulfate/polyacrylamide gel electrophoresis after chondroitinase ABC treatment of the proteoglycan revealed a large difference in their sizes. The cartilage proteoglycan core protein had a molecular weight of about 200,000 while the yolk sac tumor proteoglycan core protein migrated with an apparent molecular weight of about 20,000. In addition, the cultured yolk sac tumor cells that make the small proteoglycan did not react with antiserum against the cartilage proteoglycan. These results indicate that the proteoglycan isolated from the yolk sac tumor is similar to the small chondroitin sulfate proteoglycan species found in cartilage and support the existence of at least two dissimilar and genetically independent chondroitin sulfate proteoglycan core proteins.
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PMID:Immunological evidence for two distinct chondroitin sulfate proteoglycan core proteins: differential expression in cartilage matrix deficient mice. 640 83

Three types of murine tumors, B-16 melanoma, A-10 carcinoma, and S-180 sarcoma, were shown to contain elevated glycosaminoglycan (GAG) concentrations in vivo as compared to normal muscle or subcutaneous tissue. Hyaluronate was especially concentrated in the A-10 carcinoma, which contained approximately six times more hyaluronate than subcutaneous tissue and 18 times more than muscle. In all three tumors, chondroitin sulfates, especially chondroitin-4-sulfate, were present in higher concentrations than in the normal tissues. In culture, however, all three tumor cell lines produced less than 5% as much GAG as mouse fibroblasts, when measured by incorporation of [3H] acetate or by chemical analysis. Varying the culture passage number or the medium composition, ie, glucose, serum, and insulin concentrations, had little effect on GAG synthesis by the tumor cells. The low GAG levels in the tumor cell cultures were not due to hyaluronidase activity in their media. In an attempt to mimic possible host-tumor cell interactions that could account for the elevated GAG levels in vivo, tumor cells were cocultured with fibroblasts, but no stimulation above the amount made by the tumor cells alone plus that by the fibroblasts alone was observed. Conditioned media from the tumor cells, either dialyzed or not against fresh complete medium, had no effect on fibroblast GAG synthesis. Tumor extracts, however, were found to stimulate synthesis of hyaluronate by fibroblasts. Stimulation by extracts of A-10 carcinoma was greater than and additive to that of serum. The above results strongly suggest that GAG production in these tumors is in part regulated by host-tumor interactions.
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PMID:Stimulation of glycosaminoglycan production in murine tumors. 651 22

Several types of tumors contain high concentrations of hyaluronate, yet isolated tumor cells in culture often produce little glycosaminoglycan. To explore the possibility that interactions between tumor cells and host fibroblasts stimulate hyaluronate synthesis, human tumor cells were grown separately from and in coculture with normal human fibroblasts. Stimulation was observed with each of the three types of tumor cells used: LX-1 lung carcinoma, DAN pancreatic carcinoma, and TRIG melanoma. The interaction between LX-1 cells and fibroblasts was studied in detail. Under serum-free conditions, cocultures of LX-1 and fibroblasts synthesized 3-fold more hyaluronate than the sum of that produced by LX-1 and fibroblast cultures grown separately. This stimulation was linear over 72 hr and hyaluronate represented 80% of the glycosaminoglycan synthesized. Maximum stimulation occurred at a ratio of fibroblasts to LX-1 cells of 1-2:1. Quantitation of unlabeled glycosaminoglycans by HPLC analysis of disaccharides generated by digestion with chondroitin ABC and AC lyases (EC 4.2.2.4 and 4.2.2.5) demonstrated that net accumulation of hyaluronate increased 2-fold and that hyaluronate represented 80% of total chondroitinase-sensitive glycosaminoglycan produced by the cocultures. The disaccharide patterns obtained showed that accumulations of chondroitin-4- and chondroitin-6-sulfates were stimulated proportionately to that of hyaluronate in these cocultures. Similar levels of stimulation due to coculture were obtained in serum-containing and serum-free media. Stimulation was not effected by addition of LX-1-conditioned medium to fibroblast cultures or by culturing LX-1 and fibroblasts under conditions where they shared the same medium but were physically separated. Cell contact between LX-1 and fibroblasts thus appears to be necessary for the stimulation of hyaluronate synthesis.
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PMID:Interactions between human tumor cells and fibroblasts stimulate hyaluronate synthesis. 659 27

A 2 1/2-year-old boy had a slowly enlarging mass at the site of a typical iris-ciliary body coloboma for 2 years. The mass was excised partially by iridocyclectomy. By light microscopy, the tumor cells were embedded in a rich mucoid stroma that contained abundant hyaluronidase-sensitive acid mucopolysaccharides. By electron microscopy the tumor showed light and dark cells with interdigitating cell membranes, desmosomes, gap junctions, multilaminar basement membrane, and numerous extracellular collagen fibrils that resembled vitreous fibrils. We believe that the tumor represents a hamartomatous (congenital) adenoma of the nonpigmented ciliary epithelium rather than a conventional (acquired) adenoma, since it developed precisely within a colobomatous defect of the iris and ciliary body.
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PMID:Hamartomatous adenoma of the nonpigmented ciliary epithelium arising in iris-ciliary body coloboma. Light and electron microscopic observations. 667 54

The epipodophyllotoxin derivatives, etoposide (VP-16) and teniposide (VM-26), are highly lipophilic anticancer drugs supplied with novel commercial solvent systems. A BALB/c mouse skin toxicity model was used to evaluate the ulcerative potential of intradermal (ID) VP-16 and its lipophilic solvent system along with the main ingredient of the VM-26 solvent, polyethoxylated castor oil (PECO). ID VP-16 caused dose-dependent ulceration following 0.17 mg, 0.33 mg (50 mg/M2) or 1.0 mg (150 mg/M2). Both normal saline (0.05 ml ID) and hyaluronidase (7.5 u ID) were effective as local VP-16 antidotes, presumably by diluting out the extravasated drug. The VP-16 solvent alone was as toxic as the 1.0 mg (undiluted) ID VP-16 injection. ID PECO was mildly ulcerative in mouse skin. When given to P-388 lymphocytic leukemia-bearing mice, both VP-16 (24 mg/kg IP for 3 doses) and VM-26 (8 mg/kg IP for 2 doses) were active, producing increased life spans (ILS) of 160% and 90%, respectively. The solvents, given IP at the same schedule, did not increase or decrease the life span of tumor-bearing mice, but did increase morbidity. In an in vitro human tumor clonogenic assay (WiDr colon carcinoma and HEC-1A endometrial carcinoma in soft agar), both VP-16 and VM-26 showed moderate to complete inhibition of tumor colony forming units (TCFUs) by continuous exposure. 1-h drug exposures were marginally active at reducing TCFUs. None of the epipodophyllotoxin diluents at clinical concentrations reduced TCFUs. At very high concentrations, both epipodophyllotoxins were cytotoxic. They were more effective at reducing TCFUs when plated as a continuous exposure rather than a 1-h exposure.
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PMID:Skin ulceration potential without therapeutic anticancer activity for epipodophyllotoxin commercial diluents. 667 64

Rat 13762NF mammary adenocarcinoma cell surface glycoproteins from s.c. tumor- or lung metastases-derived cell clones of differing spontaneous metastatic potentials were examined for their relationship to metastasis. After treatment with neuraminidase, lectin-binding assays showed that highly metastatic clone MTLn3 cells express approximately twice the quantity of peanut agglutinin (PNA) binding sites (approximately 2.3 X 10(8) sites/cell) than clones of lower metastatic potential. However, the number of wheat germ agglutinin (WGA)-binding sites on the various cell clones decreased slightly as the metastatic potential of the clones increased. The quantities of concanavalin A (conA)-binding sites were similar (approximately 1.7 X 10(8) sites/cell) in all cell clones and growth conditions. Glycoprotein analysis was performed by electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate (SDS-PAGE) and subsequent staining with 125I-labeled lectins. SDS-PAGE gels stained with 125I-labeled conA revealed mainly one glycoprotein (Mr approximately 150 kD), and the amounts of this glycoprotein did not correlate with metastasis. Differences in WGA-binding glycoproteins were detected between s.c. tumor- and lung metastases-derived cell clones. Several desialylated glycoproteins were detected with 125I-labeled PNA after SDS-PAGE, and the labeling intensity of one (Mr approximately 580 kD) correlated with the metastatic potentials of the various cell clones. This high Mr galactoprotein was further analyzed by [3H]glucosamine metabolic labeling, solubilization, sequential gel filtration, and chondroitinase ABC treatment prior to SDS-PAGE. The 580 kD galactoprotein was expressed in increased amounts on the more highly metastatic clones. Chemical labeling of cell surface sialic acid residues using periodate treatment followed by [3H]borohydride reduction showed an additional change in a major sialoglycoprotein (Mr approximately 80 kD), which decreased in labeling intensity on clones of increasing metastatic potential. The results suggest quantitative changes in cell surface glycoproteins rather than major qualitative alterations are associated with differences in the metastatic behavior of 13762NF tumor cell clones.
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PMID:Cell surface glycoproteins of 13762NF mammary adenocarcinoma clones of differing metastatic potentials. 668 89

Changes in the structure of the surface of mastocytoma cells were induced by hyperthermia and were investigated by means of cell electrophoresis. A decrease in the cell electrophoretic mobility was detected as early as 15 min after treatment at 42 degrees and progressed more rapidly under hypoxic conditions than under oxic conditions. Subsequent recovery of electrophoretic mobility at 37 degrees was dependent on the length of heat treatment and oxygenation. The surviving fraction of cells detected by their colony-forming ability and the fraction of electrophoretically recovered cells 24 hr after exposure to hyperthermia showed a good statistical correlation. It was suggested that the mechanism of electrophoretic mobility reduction by heating was the vertical translocation of hyaluronidase-sensitive charge from the peripheral layer into a deeper layer by combined use of specific enzymes and stepwise different ionic strengths. These results suggest the importance of irreparable changes of membrane conformation in the loss of colony-forming ability of heated tumor cells.
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PMID:Effects of hyperthermia on cell surface charge and cell survival in mastocytoma cells. 679 30

A proteoglycan was isolated from ascites fluid produced by a rat yolk sac tumor. The glycosaminoglycan chains of the proteoglycan are all sensitive to digestion with chondroitinase ABC and about 90% are sensitive to chondroitinase AC. The proteoglycan contains 5% protein. Amino acid analysis revealed a high content of serine and glycine which together constitute 37% of the amino acids. Glutamic acid (glutamine) and aspartic acid (asparagine) are also abundant. Galactosamine accounts for 97% of the hexosamine and the remainder is glucosamine. These characteristics indicate that the glycosaminoglycan side chains of this proteoglycan are predominantly chondroitin sulfate with a smaller amount of dermatan sulfate. Antibodies to the proteoglycan were prepared by immunization of a rabbit with purified alkali-treated proteoglycan. Affinity-purified antibodies from the antiserum immunoprecipitated (35S)sulfate-labeled radioactivity from culture media of the yolk sac tumor cells known to contain chondroitin sulfate proteoglycan. This binding was inhibited by the intact purified proteoglycan but not by proteoglycan treated with papain, suggesting dependence of the reactivity of the antibodies on integrity of the protein part of the proteoglycan. Immunofluorescence of the cultured yolk sac tumor cells revealed localization of immune reactive proteoglycans at the cell surface.
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PMID:Isolation of a chondroitin sulfate proteoglycan from a rat yolk sac tumor and immunochemical demonstration of its cell surface localization. 679 88

A transplantable colorectal adenocarcinoma and the normal colonic mucosa derived from rats of ACI/N strain were digested successively with pronase, deoxyribonuclease, chondroitinase ABC, and heparitinase to obtain the corresponding glycopeptide fractions. The amino acid compositions of these two fractions suggested that the polypeptide backbones were quite similar. However, the electrostatic net charges of these fractions were shown to be different by cellulose acetate membrane electrophoresis, ion exchange chromatography, and measurement of sialic acid contents. The glycopeptide fraction derived from adenocarcinoma contained much greater quantities of less acidic glycopeptides than that derived from the normal colonic mucosa. The former exhibited much stronger blood group A and H activities than the latter. Moreover, the former reacted with Ricinus communis lectin I, whereas the latter did not react with this lectin. These results indicate that the carbohydrate structures of tumor sialoglycoproteins are different from those of the corresponding ones in the normal tissue from which the tumor has originated.
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PMID:Sialoglycopeptides obtained from a transplantable rat colorectal adenocarcinoma: a comparison with those from normal colonic mucosa. 688 96


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