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

15 cases of human malignant melanoma were studied and classified into 5 superficial speading (SSM), 5 nodular melanomas (NM), and 5 melanoma metastasis (Met). The tissue was fixed with formaldehyde and cetylpyridium chloride (CPC). Glycosaminoglycans (GAG) or proteoglycans respectively were characterized by Alcian blue staining following the method of critical electrolyte concentration (CEC) (Scott, Dorling 1965) and by testes hyaluronidase. The staining intensities were quantified by a Leitz MPV photometer microscope in basement membranes (BM) and tumor septa. Tumor septa, which may be looked on as correlates of epithelial BM material, show increased straining intensities as compared to the normal BM (nBM) around the tumor. It is concluded from the sensitivity to testes hyaluronidase and the straining pattern that these are caused by increased straining of GAG of the type of chondroitin sulfates and possibly of dermatan sulfate while unsulfated GAG are rather decreased. The GAG pattern in BM in SSM shows characteristics of tumor septa and of nBM as well. The staining of the tumors shows higher intensities than that of all structures in the normal skin. It is concluded that increasing malignancy is accompanied by increasing changes in GAG which can be quantified by the method used topohistochemically discerning the healthy tissue from malignant structures.
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PMID:[Histotopochemical quantification of glycosaminoglycans in melanomas and the surrounding epidermis]. 209 11

Confluent adult and fetal human glomerular epithelial cells were incubated for 24 h in the presence of [3H]-amino acids and [35S]sulfate. Two heparan-35SO4 proteoglycans were released into the culture medium. These 35S-labeled proteoglycans eluted as a single peak from anion exchange chromatographic columns, but were separable by gel filtration on Sepharose CL-6B columns. The larger heparan-35SO4 proteoglycan eluted with the column void volume and at a Kav of 0.26 from Sepharose CL-4B columns. The most abundant medium heparan-35SO4 proteoglycan was a high buoyant density proteoglycan similar in hydrodynamic size (Sepharose CL-6B Kav 0.23) to those previously described in glomerular basement membranes and isolated glomeruli. Heparan-35SO4 chains from both proteoglycans were 36 kDa. A smaller proportion of Sepharose CL-6B excluded dermatan-35SO4 proteoglycan was also synthesized by these cells. The predominant protein cores of both medium heparan-35SO4 proteoglycans were approximately 230 and 180 kDa. A hybrid chondroitin/dermatan-heparan-35SO4 proteoglycan with an 80-kDa protein core copurified with the smaller medium heparan-35SO4 proteoglycan. This 35S-labeled proteoglycan appeared as a diffuse, chondroitinase ABC sensitive 155-kDa fluorographic band in sodium dodecyl sulfate-polyacrylamide gels after the Sepharose CL-6B Kav 0.23 35S-labeled proteoglycan fraction was digested with heparitinase. The heparitinase generated heparan sulfate proteoglycan protein cores and the 155-kDa hybrid proteoglycan fragment had molecular weights similar to those previously identified in rat glomerular basement membrane and glomeruli using antibodies against a basement membrane tumor proteoglycan precursor (Klein et al. J. Cell Biol. 106, 963-970, 1988). Thus, human glomerular epithelial cells in culture are capable of synthesizing, processing, and releasing heparan sulfate proteoglycans which are similar to those synthesized in vivo and found in the glomerular basement membrane. These proteoglycans may belong to a family of related basement membrane proteoglycans.
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PMID:Partial characterization of proteoglycans synthesized by human glomerular epithelial cells in culture. 210 32

A case of a malignant mesothelioma of the tunica vaginalis is presented. The patient with an intrascrotal mass was a 32-year-old Japanese male who had no history of asbestos exposure. The tumor was located on the surface of the right testis and was composed of columnar to polygonal cells with glandular and papillary structures. It showed many mitoses and focal invasion of the tunica albuginea. The tumor cells contained alcian blue- and Hale's colloidal iron-positive, hyaluronidase-digestible materials. Immunohistochemical stains for cytokeratin and vimentin were positive, while those for carcinoembryonic antigen, epithelial membrane antigen, Leu-M1, and factor VIII-related antigen were negative. The systemic examinations revealed no other tumors. Based on these findings the tumor was diagnosed as malignant mesothelioma of the tunica vaginalis. The differential diagnosis is discussed under the histologic, histochemical, and immunohistochemical points of view and the previous literature is reviewed.
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PMID:Malignant mesothelioma of the tunica vaginalis. 228 93

Several years of clinical chemotherapy have shown that, despite modern refinements, cytotoxic agents are not able to eradicate metastases of most adult solid tumors but only to prolong survival by achieving a cell kill that is not 100 per cent. Among the possible causes of this phenomenon, two are discussed in detail. The first one is cell autonomy. It is shown that the numbers of generations reached by a metastatic clone until clinical detection is largely in excess of 100, which allows for a considerable number of mutations, and that in addition genetic destabilization leading to autonomy proceeds much more rapidly than anticipated by a random mutation process. Adaptative changes by genetic amplification in response to toxic injury add to this acceleration effect, accounting for the fact that most metastatic cells are totally resistant very early in the natural history of a human tumor. On the other hand, it is shown that dormant metastatic cells do exist, due either to lack of autocrine growth factors or to inhibiting agents secreted by other metastases. These cells can survive chemotherapy and then re-enter a proliferative state due to some mechanisms that are analyzed, accounting for semi-late and late failures. These obstacles call for other strategies of metastases management, such as arresting or differentiating agents, some of which have been successfully tested by the author's group, such as antiprostaglandins, antithrombin, somatostatin, hyaluronidase, and retinoic acid. It remains to study their optimal combinations, and the appropriate timing, in order to achieve, if not eradication, growth suppression for very long periods without toxicity.
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PMID:Accelerated genetic destabilization and dormancy: two distinct causes of resistance in metastatic cells; clinical magnitude, therapeutic approaches. 240 88

Two cases of an aggressive cutaneous carcinoma showed both squamous and adenomatous differentiation. These neoplasms invaded subcutaneous structures with a sclerosing pattern, making surgical resection difficult. Unlike the usual squamous carcinoma, glands and epithelial mucin (sialomucin) were produced. This mucin stained with mucicarmine and was sensitive to sialidase and resistant to hyaluronidase digestion. No mucin with similar histochemical properties was found in a study of 50 consecutive cutaneous squamous carcinomas and 50 consecutive basal cell epitheliomas from our files. Literature reports of histologically similar cutaneous carcinomas together with our experience with these two cases suggest aggressive behavior for this category of neoplasm.
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PMID:Adenosquamous carcinoma of the skin. An aggressive mucin- and gland-forming squamous carcinoma. 240 85

Many glioma-derived cell lines have the capability of escaping cell-mediated immune attack. One mechanism of escape is the secretion of a hyaluronidase-sensitive mucopolysaccharide coat by these cells. This coat prevents contact and tumor cell killing by specific cytolytic allogeneic lymphocytes. The production of the coat by the tumor cells is stimulated by a macromolecular factor released by peripheral blood mononuclear (PBMC) cells in culture. We have examined the morphologic and ultrastructural features of this extracellular matrix. Three coat-producing lines were studied. Under phase contrast light microscopy, the coat is a clear pericellular 'halo'. To stain this zone, ruthenium red and Alcian Blue 8 G stains, which bind to acid mucopolysaccharides (to a large extent, hyaluronic acid), were used. The two stains produced similar results. With light microscopy, a weblike pattern of stain was evident throughout the halo region. With transmission electron microscopy, staining was found along the plasma membrane of the glioma cells and their microvilli, stretching in long, branching filaments from these surfaces and, in some instances, from one microvillus to the next. Since mucopolysaccharide matrices have a large aqueous component, it was necessary to determine whether dehydration alters the stain pattern. Therefore, undehydrated ruthenium red stained specimens from each culture were embedded in Quetal 651 (Ted Pella, Inc., Tustin, CA), a water soluble plastic. No morphologic differences were noted between the hydrated and dehydrated specimens. This study indicates that numerous long microvilli and a secreted mucopolysaccharide matrix are important structural elements of the lymphocyte-stimulated tumor cell halo in vitro. The mechanism by which the PBMC factor stimulates coat formation and the importance of the coat in in vivo tumor defenses remain to be elucidated.
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PMID:Ultrastructural features of the lymphocyte-stimulated halos produced by human glioma-derived cells in vitro. 242 Sep 43

A hyaluronidase-sensitive component of human peritoneal fluid from a patient with Wilms' tumor when injected into rabbits has been shown to suppress the formation of humoral precipitating antibodies to certain major classes of proteins present in the fluid. Furthermore, it has been found that hyaluronic acid, when included with certain test antigens (serum albumin, fetuin) or antigen mixtures (tumor isolates or mixtures of albumin, immunoglobulin G and immunoglobulin M), produces a marked distortion or complete blockage of immunoelectrophoresis precipitin arcs, as well as altered gel chromatography elution profiles. These findings that hyaluronic acid can interfere profoundly with both the elicitation of a complete antibody response and the formation of "normal" patterns of antigen-antibody precipitates in laboratory tests supports the possibility that this polysaccharide may play an immuno-regulatory role by masking potential immunogens. Consideration of the mechanisms for these in vivo and in vitro effects suggests that there may be some common basis in an "excluded volume" property of the hyaluronate, but this does not appear sufficient to explain the complexity and selectivity of the observed phenomena.
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PMID:The selective suppression of immunogenicity by hyaluronic acid. 242 4

Cytotactin is an extracellular matrix protein that is involved in neuron-glia adhesion and is found in both neural and nonneural sites. It is synthesized by glia but not by neurons. In this study, we have examined the binding of cytotactin to a variety of extracellular matrix components using uniform microscopic beads (Covaspheres) that could be labeled and then linked to purified molecules. Cytotactin-coated beads bound well to neurons, and this binding was strongly inhibited by anti-cytotactin antibodies but not by anti-neural cell adhesion molecule (anti-N-CAM) antibodies. In contrast, the binding of N-CAM-coated beads to neurons was inhibited by anti-N-CAM antibodies and not by anti-cytotactin antibodies. To identify a neuronal ligand for cytotactin, we tested several molecules for their ability to block the binding of cytotactin-coated beads to cells. A proteoglycan-containing fraction that copurified with cytotactin from brain extracts strongly inhibited binding, whereas neither a heparan sulfate proteoglycan from Engelbreth-Holm-Swarm tumor cells nor soluble cytotactin itself had a significant inhibitory effect. The neural proteoglycan also inhibited the binding of cytotactin-coated beads to fibroblasts. Digestion with chondroitinase, heparitinase, and hyaluronidase as well as immunological analyses suggested that the predominant species in the active fraction was a chondroitin sulfate proteoglycan with a Mr280,000 core protein bearing HNK-1 antigenic determinants and also indicated that hyaluronic acid was present in this fraction. In experiments on in vitro synthesis, it was found that the proteoglycan was synthesized in culture by embryonic chicken brain tissue but not by embryonic chicken glial cells. A series of binding experiments was performed on appropriately derivatized beads to confirm that the proteoglycan is a ligand for cytotactin and to check for the possibility that other extracellular matrix proteins might interact with one or the other member of this binding couple. Proteoglycan-coated beads and cytotactin-coated beads coaggregated readily. The aggregation was inhibitable by anti-cytotactin antibodies, soluble cytotactin, or soluble proteoglycan. Addition of laminin inhibited the binding of cytotactin-coated beads to proteoglycan-coated beads or to cells; this is consistent with data indicating that laminin interacts with a component of the proteoglycan-containing fraction. In contrast, fibronectin bound to cytotactin, but it did not bind to proteoglycan or interfere with the binding of cytotactin to proteoglycan. The results of this study are in accord with the idea that the functions of extracellular matrix components during neural and nonneural development may be modulated both by competition for shared cell surface receptors and by a network of molecular interactions among the matrix components themselves.
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PMID:A proteoglycan with HNK-1 antigenic determinants is a neuron-associated ligand for cytotactin. 243 34

A mesothelial, endothelial and epithelial differentiation of the adenomatoid tumors is discussed in the literature. Aimed at this problem the cellular nature of 12 adenomatoid tumors was investigated by means of histochemical and immunohistochemical methods at light and electron microscopic level. In all these neoplasias prekeratin was demonstrated while factor VIII-associated antigen and myoglobin were lacking within the tumor cells. The ultrastructural picture of the tumor cells was similar to that of mesothelial cells; abundant intermediate filaments of the keratin type could be decorated by means of the protein A-gold technique in them. Furthermore hyaluronidase sensitive glycosaminoglycans but no sulfated and neutral mucoproteins were found. The results suggest a mesothelial nature of the tumor cells of adenomatoid tumors.
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PMID:Adenomatoid tumors--mesotheliomas or not? A histochemical, immunohistochemical and light and electron microscopic (TEM/SEM) study. 243 54

A rare case of adenomatoid tumor arising in the ovary is presented. At autopsy on a 61-year-old woman, a soft, solid and cystic tumor, measuring 0.8 X 0.7 cm, was detected in the hilus of the left ovary. Light microscopic study showed characteristic features of adenomatoid tumor. Alcian blue stain, with and without hyaluronidase pretreatment, revealed the presence of hyaluronic acid on the luminal surface and in the vacuoles of the tumor cells. Immunohistochemical stains of tumor cells were positive for low-molecular-weight cytokeratin (PKKL), vimentin, and carbohydrate antigen (CA) 125, whereas they were focally positive for high-molecular-weight cytokeratin (34 beta E12). They were negative for factor VIII-related antigen (FVIII-RAG), Ulex europaeus I lectin (UEA I), carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Ultrastructural studies disclosed surface microvilli and bundles of tonofilaments. These observations strongly support the idea of this tumor being of mesothelial origin.
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PMID:Adenomatoid tumor of the ovary: an immunohistochemical and ultrastructural study. 245 35


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