Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0268596 (EMA)
 2,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Radiation grafted hydrogels on silicone rubber with water contents ranging from 10--90% have been evaluated by the vena cava ring test. All hydrogel grafted materials were found to accumulate less thrombus than ungrafted silicone rubber, and graft level was found to have little effect on thrombus accumulation. Acrylamide grafts demonstrated superior thromboresistance by this test. Poly (2-hydroxyethyl methacrylate-ethyl methacrylate (HEMA/EMA) copolymers were examined along with pure HEMA and EMA grafts. At two weeks implantation, intermediate HEMA/EMA copolymers were found to have the least thrombus accumulation of any of the polymers in this series. EMA grafted rings were highly thrombogenic. The results from these studies indicate that the sensitivity of the vena cava ring test for detecting certain differences in polymer structure is poor. Also, the significance of the vena cava ring test for evaluating materials for use in contact with flowing human blood is questionable, based upon comparisons of results for similar materials tested in other blood compatibility evaluation systems.
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PMID:The thrombogenicity of radiation grafted polymers as measured by the vena cava ring test. 71 23

A series of studies was conducted on the synthesis of polyfunctional cyclophosphazene monomers having radiopacity and a polymerization group in the same molecule, and their properties and applicability to composite resin were examined. Using octachlorocyclotetraphosphazene, P4N4Cl8 (4PNC), monomers were synthesized by replacing the 1-4 of chlorine (Cl) with p-bromophenol (BrC6H4OH, BrPh), and replacing the residual number of Cl, 7-4, with 2-hydroxyethyl methacrylate [CH2:C(CH3)COOCH2CH2OH](HEMA), so as to obtain four kinds of transparent monomer having radiopacity and a polymerization group in the same molecule. We then analyzed these monomers and examined their physical properties after bulk-polymerization. Next, we prepared an organic composite filler using 4PN-(BrPh)3-(EMA)5 monomer, which showed comparatively good radiopacity, to produce a new experimental radiopaque composite resin. Although radiopacity improved in accordance with the increase in the number of BrPh molecules replaced, the mechanical properties of the polymer became poorer. Similarly it was proved that the radiopacity of composite resin made with 4PN-(BrPh)3-(EMA)5 monomer was equivalent or even superior, compared with the radiopacity of the front tooth. Consequently, it was shown that these synthesized monomers can be applied to visible light-cured radiopaque composite resin.
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PMID:Synthesis of radiopaque cyclophosphazene monomers, properties of bulk polymers and their application to composite resin. 128 48

Fibrinogen adsorption from blood to biomaterials may regulate platelet adhesion and thrombus formation because of fibrinogen's central role in the coagulation cascade and its ability to bind specifically to the platelet membrane glycoprotein (GP) IIb-IIIa. Adsorption of fibrinogen from blood plasma to many materials exhibits a maximum with respect to plasma dilution and exposure time (the Vroman effect). In this study fibrinogen adsorption to several polymers was examined to ascertain the influence of controlled changes in surface chemistry on the Vroman effect. The materials included hydroxyethylmethacrylate-ethylmethacrylate (HEMA/EMA) copolymers, Biomer, and a series of segmented polyurethanes (PEUs), two of which contained fluorinated chain extenders. Each material exhibited maximal adsorption of fibrinogen at intermediate plasma concentrations. Little effect of soft-segment type or molecular weight was observed and no significant differences in fibrinogen adsorption to the fluorinated PEUs were seen. Changes in the strength of fibrinogen attachment to these materials with time after adsorption were also assessed. Fibrinogen adsorbed for 1 min was displaced more readily by blood plasma than that adsorbed for 1 h, regardless of the material. The more hydrophobic polymers exhibited greater retention of adsorbed fibrinogen. In addition, the fraction of fibrinogen retained by polyethylene depended on the amount of fibrinogen adsorbed to the surface, being greatest when the surface loading was the least. These studies indicate that spreading or transition of adsorbed fibrinogen molecules from a weakly to tightly bound state is a general consequence of protein adsorption to solid surfaces.
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PMID:Changes in fibrinogen adsorbed to segmented polyurethanes and hydroxyethylmethacrylate-ethylmethacrylate copolymers. 148 67

To study the histogenesis of and determine the most useful markers for diagnosing anaplastic thyroid carcinoma (ATC), 32 cases, including 2 with numerous osteoclast-like cells, were stained with a battery of antibodies to epithelial (keratin, epithelial membrane antigen [EMA], carcinoembryonic antigen [CEA]), mesenchymal (vimentin, desmin, muscle-specific actin [MSA], Factor VIII-related antigen [FVIII:RAg]), endocrine (thyroglobulin, calcitonin, chromogranin [Cg]), lymphocytic (leukocyte common antigen [LCA]), histiocytic (alpha-1-antitrypsin [alpha 1AT], alpha-1-antichymotrypsin [alpha 1AChy], KP1), melanocytic (HMB-45), and Schwann cell (S-100 protein) markers. Five tumors were associated with papillary carcinoma. In one of these cases, a morphologic continuum between the well-differentiated carcinoma and the ATC was visualized by their positive immunostaining for both vimentin and keratin, thus supporting the hypothesis that the latter tumor originated from the former. Twenty-five (78.1%) tumors expressed keratin, 10 (31.3%) reacted for EMA, and 3 (9.4%) expressed CEA, confirming the epithelial nature of this neoplasm. Reactivity for thyroglobulin was seen in a small number of cells in five (15.6%) thyroglobulin was seen in a small number of cells in five (15.6%) ATCs. Because all of the cases that expressed keratin also stained positively for EMA, CEA, or thyroglobulin, it is believed that keratin is the most useful epithelial marker for diagnosis of ATC. A lack of reactivity for calcitonin and Cg indicates that these tumors are not derived from C cells, as has been proposed by some authors. Reactivity for KP1 (CD68), a monoclonal antibody that reacts with a macrophage-associated antigen, occurred in the osteoclast-like cells but not in the anaplastic tumor cells. This finding, together with negative keratin staining of the osteoclast-like cells, indicates that these cells are not epithelial in nature and therefore should be considered reactive rather than neoplastic. Thirty tumors (93.8%) expressed vimentin, 15 (46.9%) marked for alpha 1AChy, 11 (34.4%) exhibited alpha 1AT, and 11 (34.4%) expressed S-100 protein. Because all of these markers can be seen in a wide variety of tumors of different histogeneses, they have no value in the diagnosis of ATC. Although immunostaining for FVIII:RAg, desmin, and MSA was negative in all of these tumors, these markers can help to differentiate between ATCs and some soft tissue sarcomas with which they can be confused.
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PMID:Anaplastic thyroid carcinoma. Immunocytochemical study of 32 cases. 171 40

Light microscopic, immunohistochemical and ultrastructural studies were performed on a surgically removed left atrial myxoma containing glandular structures. Routine examination showed glandular lumina lined by cylindric epithelium in the characteristic myoxoid stroma, and the glands contained PAS positive mucin. The glandular structures demonstrated significant positivity for wide-spectrum-CK, EMA, and moderate positivity for CEA. Stromal cells were positive for vimentin, FVIII. Ag was present only in surface cells and blood vessels. Ultrastructurally the gland showed characteristics of mucin secreting epithelium. The authors briefly overview the currently existing theories about the histogenesis of myxomas.
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PMID:[Glandular myxoma of the heart]. 759 93

The effect of substrate surface hydrophobicity on fibronectin (Fn) adsorption and endothelial cell adhesion strength was studied. Bovine aortic endothelial cells (BAEC) were plated for 2 h with and without preadsorbed Fn on slides coated with homopolymers and copolymers of hydrophilic polyhydroxyethylmethacrylate (polyHEMA) and hydrophobic polyethylmethacrylate (polyEMA). The polarity of the substrate was determined by Wilhelmy plate contact angle. The amount of adsorbed Fn was determined using 125I-labeled Fn. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy was used to detect gross conformational changes of adsorbed Fn on polyHEMA or polyEMA. BAEC were cultured in serum-free medium for 2 h and subjected to a brief exposure of laminar flow in a variable-height flow chamber that provided a range of shear stresses of 15-185 dynes/cm2. The critical shear stress to detach 50% of the cells increased with increasing EMA content to a maximum at 20% HEMA/80% EMA copolymer irrespective of the presence of preadsorbed Fn. However, the critical force increased even though there were similar amounts of Fn adsorbed on all substrates. ATR-FTIR spectroscopy showed only minor changes in beta-sheet structure of Fn adsorbed to polyHEMA and polyEMA. These results show that the force to detach cells did not increase solely with increasing amounts of adsorbed Fn; rather, these results indicate a more complex interplay involving both the amount and conformation of adsorbed Fn.
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PMID:Effect of fibronectin amount and conformation on the strength of endothelial cell adhesion to HEMA/EMA copolymers. 878 1

Plasma protein adsorption is an important initial event in the response of tissue to foreign materials. Little is known about the way in which the chemical properties of materials influence the nature of the adsorbed layer and thus the later cellular responses. In this study, the amounts of fibrinogen, immunoglobulin G, albumin, and hemoglobin adsorbed from plasma to a series of HEMA-EMA random copolymers varying in hydrophilicity was measured. The adsorption of each protein varied in a characteristic way with copolymer composition probably reflecting a different affinity of the proteins for the various copolymers. A complex variation in the composition of the adsorbed protein layer on polymers varying in hydrophilicity was thus evident. Surface enrichment of the proteins, calculated as the ratio of the surface and bulk fraction of each protein, also varied with copolymer composition, and indicated substantial differences in the composition of the surface and bulk phases. Surface area variations among the copolymers, preferential adsorption of 125I proteins, and the possibility of structural degradation of 1,25I proteins in plasma were investigated but did not appear to influence the adsorption results. The ability of polymers to fractionate plasma proteins and concentrate them at their surface is concluded to be a key factor in the complex processes which determine the compatibility of polymers in vivo.
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PMID:Adsorption of proteins from plasma to a series of hydrophilic-hydrophobic copolymers. II. Compositional analysis with the prelabeled protein technique. 1265 35

A visible light-curing calcium hydroxide cement is presented here and the effects of its resin matrix on the Ca2+ releasing, compressive strength of set material and the pH value of water in which set materials immersed are evaluated. Experimental results show that the effects of the selected resin matrix on Ca2+ releasing, compressive strength and pH value are significant. The calcium hydroxide cement containing BEMA or EMA and HEMA as resin matrix has good properties. The pulp capping test showed that an excellent dentin bridge appeared in dogs capped teeth at 70 days. pulp, pulp capping, calcium hydroxide, visible light-curing, dental materials
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PMID:[Development of a visible light-curing calcium hydroxide cement]. 1612 23

Elution of organic compounds from resin-based dental fillings during their application in the human mouth environment may have a potential impact on the human health. Ethanol, water and other solvents very often present in the human mouth have the ability to penetrate dental fillings placed in the human tooth. Penetration of liquids into the tooth may lead to the liberation of unreacted dental filling ingredients or their degradation products. Determination of these compounds is necessary for better knowledge from possible harmful effects caused by dental fillings. The aim of this study was the isolation and identification of compounds released from resin-modified glass-ionomer cements (RMGICs), resin-based dental materials applied in dentistry. Compounds were extracted from fillings by using four solvents (40% ethanol, water, 1% acetic acid and artificial saliva). Liquid samples containing eluted compounds were then extracted, evaporated and analyzed by using of HPLC-MS (high-performance liquid chromatography-mass spectrometry) and HPLC-DAD (high-performance liquid chromatography-diode array detection) techniques. Almost thirty components (monomers and additives) of RMGICs were identified. The main identified extractables were: Bis-GMA (bisphenol A glycidyl dimethacrylate), Bis-EMA (ethoxylated bisphenol A dimethacrylate), UDMA (urethane dimethacrylate), TEGDMA (triethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate) as monomers and diphenyliodonium chloride, camphorquinone (initiators), BHA (inhibitor), 4-(dimethylamino) ethyl benzoate (co-initiator) as additives.
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PMID:Identification of organic extractables from commercial resin-modified glass-ionomers using HPLC-MS. 1682 88

Angiosarcomas of the major salivary glands are rare tumours. The authors describe a case of the tumour located in the right parotid gland of a 77-year-old woman. Histological examination revealed a poorly differentiated tumour made up of epithelioid and spindle cells. These two types of cells intermingled. In some parts, primitive mutually anastomosing irregularly shaped vascular spaces with atypical endothelial cells were found. The tumour cells were positive for CD31, CD34, EMA and FVIII (focally). Due to the relatively short follow-up period the prognosis of the disease is difficult to estimate.
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PMID:Angiosarcoma of the parotid gland. 1976 60


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