Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seventy-eight contact lens patients issued with soft HEMA lenses were examined in order to establish reasons for intolerance. The examination was carried out in conjunction with a questionnaire designed to furnish information about the habits of the contact lens patients. Less than 50% of the patients had been advised to have their lenses checked. Almost all the patients wore their contact lenses all day without interruption. On average they had been wearing the lenses for up to 17 hours per day over a 3.3 year period. In approximately 2/3 of the cases the eye had suffered some damage and in approximately 1/3 of the cases the effects were more serious. Patients who had worn their lenses for even longer periods of time had suffered still more severe eye damage. However, microbiological findings, allergies to the cleaning fluids, reduced tear production, incorrect lens fit and severe deterioration of the lens material were not found to be the prime causes of intolerance. Photographs shot by SEM showed evidence of defects of the corneal surface after the HEMA lens had been worn 18 hours.
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PMID:[Damage caused by wearing contact lenses throughout the day]. 734 80

A plasma polymerized HEMA (ppHEMA) film was prepared by plasma deposition polymerization onto an elastic material, silicone rubber. The surfaces of control, argon plasma-treated, and ppHEMA-modified silicone rubber were characterized by ESCA, FTIR-ATR and SEM techniques. ESCA verified the respective chemical shift of control and ppHEMA-modified films. The presence of the ppHEMA was also verified by ESCA. The introduction of ppHEMA onto a hydrophobic support provided an adequate surface for rabbit corneal epithelial cell attachment and growth. Cell attachment and growth onto these surfaces were examined by light microscopy. Cell attachment onto the control and the argon plasma-treated surface was negligible, while improved attachment and growth of rabbit corneal epithelium cells was demonstrated on the ppHEMA-modified polymeric surface. The ppHEMA-modified silicone rubber surface demonstrated a confluent cell layer after 72 h.
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PMID:ppHEMA-modified silicone rubber film towards improving rabbit corneal epithelial cell attachment and growth. 839 52

Adhesion characteristics of fibroblastic baby hamster kidney (BHK) cells and epithelial Madine Darby kidney (MDBK) cells on polyurethane (PU) and polyhydroxyethylmethacrylate (PHEMA) based surfaces have been studied. PU surfaces were prepared by a classical solvent-casting procedure of Pellethane solution that contains different types of solvents, i.e., THF, dioxane and their compositions. PHEMA based surfaces were obtained by bulk polymerization of respective comonomers (HEMA, acrylic acid, AA, and dimethylaminoethylmethacrylate, DMAEMA) in the presence of the crosslinker. Thus, a number of polymeric surfaces were obtained with different surface charges (COO- and NH+4) and with different surface free energies in a range between 60-82 ergs/cm2. Surface properties of these membranes were characterized by equilibrium water contents, air and octane contact angles, surface free energies, SEM photographs and ATR-FTIR spectra. Interactions of BHK and MDBK cells with the surfaces were examined in stationary culture conditions which were carried out in MEM supplemented with fetal calf serum. The observations strongly suggested that the chemical and/or physical properties of membrane surface and morphology of the cell control the degree of cell adhesion to the PU and PHEMA based membranes.
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PMID:Relationship of surface characteristics to cellular attachment in PU and PHEMA. 845 35

Gluma Dentin Bond is an adhesive system, where the primer contains 5% glutaraldehyde and 35% hydroxyethyl methacrylate. Practitioners have reported a strong desensitizing effect of the Gluma system on dentin. This study, thus, sought to evaluate the effect of this system on dentin using various microscopic techniques. 12 non-restored human molars extracted for prosthodontic reasons were used. Prior to extraction the buccal cusps were removed such that a 2 mm x 2 mm wide dentin surface was exposed. The surfaces were treated in 6 ways: (1) application of Gluma 2 cleanser, Gluma 3 primer to which 0.1% w/v fluorescein was added, and Gluma 4 sealer; (2) as in (1) but treatment with H2O/0.1% w/v fluorescein instead of the Gluma 3; (3) as in (1) but without Gluma 2; (4) as in (1) but with application of 5% glutaraldehyde instead of Gluma 3; (5) as in (1) but without Gluma 4; (6) as in (1) but with application of 35% HEMA/0.1% w/v fluorescein instead of Gluma 3. Following extraction, 1 tooth per procedure was prepared for confocal laser scanning microscopy. The remaining teeth were fixed and prepared for SEM and TEM evaluation. In specimens of procedures (1) and (5), tubular occlusions could be seen to a depth of 200 microm. In specimens of procedure (4) tubular occlusions were found only to a depth of 50 microm. Such occlusions were not seen in control specimens (2), in specimens where the smear-layer had not been removed (3), or following application of HEMA alone (6). It is concluded that glutaraldehyde can intrinsically block dentinal tubules. The septa in the tubules may counteract the hydrodynamic mechanism for dentinal sensitivity.
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PMID:Closing of dentinal tubules by Gluma desensitizer. 939 2

The effect of the inclusion of aminobenzoic acid derivatives (ABAD) in a self-etching primer comprising 4-acryloxyethyltrimellitic acid (4-AET), HEMA and water on shear bond strength to ground dentin was investigated. The mean bond strengths to dentin were significantly increased by the inclusion of 0.307 mol% ABAD in the 4-AET/HEMA primer, when compared with the control (0 wt% ABAD) (p < 0.01). A particularly high value (38.0 MPa) of shear bond strength was obtained in the use of the primer containing p-nitroanthranilic acid (p-NAA). It seemed to assume that the effect of p-NAA could be caused by the strong electron-withdrawing group of -NO2. From SEM observation, it was found that bonding resin appeared to adhere strongly to the ground dentin without formation of any resin-tags in the dentinal tubules. It was thought that the ABAD with 4-AET/HEMA could perform facilitating photo-polymerization at the bonding interface, and resulted in increased bond strength to ground dentin, and that the bond strength could be affected by the electronegativities of substitutional groups of ABAD.
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PMID:Effects of aminobenzoic acid derivatives with 4-AET/HEMA in self-etching primer on bonding to ground dentin. 955 12

An aqueous humor draining device, with size comparable to that of the Krupin tube, was constructed by using poly-HEMA material. Deposits were found on the surface of poly-HEMA when contacted in vitro with the aqueous humor of the rabbit's eye. A fibrous structure, probably composed of proteins and other macromolecules, developed on poly-HEMA surface in 15 days after the draining device was implanted into the rabbit's eye. The draining device was still in function 250 days after its implantation. SEM analysis of the retrieved poly-HEMA draining device indicated that the poly-HEMA tube opening was not blocked by any substance. These results suggest that poly-HEMA could be used as a biomaterial for construction of the aqueous humor draining device to relieve the intraocular pressure of glaucoma patients. Its long-term application awaits further investigation.
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PMID:A poly-HEMA based aqueous humor draining device. 1017 Nov

Desmopressin (DDAVP) increases plasma factor VIII coagulant activity (FVIII:C) levels in patients with mild/moderate haemophilia A. In some subjects, FVIII can be increased to haemostatic levels, thereby avoiding use of factor VIII concentrates. We reviewed our hospital's experience with 62 boys with FVIII:C levels 0.01-0.3 IU/ml who had a DDAVP challenge test (i.v. 0.3 microg/kg) following diagnosis. A therapeutic response was defined as a 1 h post-FVIII:C increase at least twofold over baseline and > 0.3 IU/ml. Of the total group, 29 (47%) boys responded to DDAVP, all of them with mild haemophilia (baseline FVIII:C > or = 0.05 IU/ml), yielding a response rate of 57% in this subgroup. Boys who responded to DDAVP had higher baseline FVIII:C levels (mean +/- SEM, 0.17 +/- 0.01 vs 0.10 +/- 0.01 IU/ml, P < 0.01) and were older (5.2 +/- 0.8 vs 3 +/- 0.4 years, P = 0.02) than those who failed to do so. The association between DDAVP response and age, however, remains unclear: seven boys who failed the initial challenge test responded to re-challenge after a mean of 6.3 years (median 4.9, range 0.5-12.5), increasing the response rate in boys with mild haemophilia to 71%. Age and FVIII:C association with DDAVP response are both important in boys with mild/moderate haemophilia A. Absence of response to DDAVP should therefore be confirmed by later re-challenge.
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PMID:DDAVP challenge tests in boys with mild/moderate haemophilia A. 1206 Jan 35

The influence of the (2-hydroxyethyl methacrylate) (HEMA) monomer addition as a comonomer to the cement liquid component and of a polymer, poly(N-vinyl-2-pyrrolidone) (PVP) to the solid component of a standard CMW-1 bone cement on gentamicin sulphate (GS) on its drug release properties have been studied. The addition of HEMA modifies the habit of the delivery curves. The incorporation of PVP into the cement matrix, apparently, did not very much modify the shape of the HEMA modified cement release curves, but led to a remarkable increase of the maximum amount of GS released. This effect was proportional to the PVP concentration incorporated. From the matrix composition and SEM data, a model based on the morphology of the matrix has been proposed. The cumulative amount of GS released by each slab Mt is most adequately fitted and represented by the equation Mt = c + at 1/2 + b[1 - exp(-nt)], which corroborates that the release occurs according to the model proposed. by means of three discrete mechanisms, namely: (i) a short-term initial elution due to the imperfections in the poly(methyl methacrylate) covering of the most external GS beads, burst effect by the buffer solution; (ii) followed by a fracture by stress cracking in an active media of the coated GS beads located on the external surface of the matrix where water molecules enter to dissolve GS molecules releasing them into the buffer solution by a diffusion-controlled process; and (iii) a third process in which the buffer solution penetrates into the internal voids and cracks creating a series of channels in a labyrinthic structure, which may facilitate the access of water molecules to the plastic-coated GS beads within the bulk matrix. This third process is enhanced by the incorporation of PVP beads as dissolved molecules within the matrix. This water-soluble additive is leachable, generating a highly porous structure in the cement. This HEMA and PVP modified cement may be used as a drug delivery system to modulate the GS release rate.
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PMID:Release of gentamicin sulphate from a modified commercial bone cement. Effect of (2-hydroxyethyl methacrylate) comonomer and poly(N-vinyl-2-pyrrolidone) additive on release mechanism and kinetics. 1216 82

Different adsorbents have been reported in the literature for protein purification. The authors have developed a novel and new approach to obtain high protein adsorption capacity utilizing a 2-methacrylamidoalanine-containing membrane. Amino acid ligand 2-methacrylamidoalanine (MAAL) monomer was synthesized using methacryloyl chloride and alanine. Poly(2-hydroxyethylmethacrylate-co-2-methacrylamidoalanine) [p(HEMA-co-MAAL)] membranes were then prepared by UV-initiated photopolymerization of HEMA and MAAL in the presence of an initiator (azobisisobutyronitrile, AIBN). The synthesized MAAL monomer was characterized by NMR. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, SEM, FTIR, and elemental analysis. These membranes have macropores in the size range of 5-10 microm. Cu(II) ions (25.9 mmol/m2) were chelated on these membranes. p(HEMA-co-MAAL) membranes were used to study the adsorption of lysozyme from aqueous media containing different amounts of lysozyme (0.1-3.0 mg/l) and at different pH values (4.0-8.0). The non-specific adsorption of lysozyme on the pHEMA membranes was negligible (0.9 microg/cm2). Incorporation of MAAL increased the lysozyme adsorption significantly up to 2.96 mg/cm2. The lysozyme adsorption capacity of the Cu(II) incorporated membranes (9.98 mg/cm2) was greater than that of the p(HEMA-co-MAAL) membranes. More than 90% of the adsorbed lysozyme was desorbed in 1 h in the desorption medium containing 1.0 M NaCl and 0.025 M EDTA. The metal-chelate affinity membranes are suitable for repeated use for more than ten cycles without a noticeable loss of capacity.
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PMID:Poly(hydroxyethyl methacrylate-co-methacrylamidoalanine) membranes and their utilization as metal-chelate affinity adsorbents for lysozyme adsorption. 1218 59

Anti-low density lipoprotein antibody (anti-LDL antibody) attached poly(2-hydroxyethyl methacrylate-methacryloylamidophenylalanine) (poly(HEMA-MAPA)) beads were prepared for selective removal of cholesterol from hypercholesterolemic human plasma. Poly(HEMA-MAPA) beads were produced by a modified suspension polymerization and then characterized by swelling tests and SEM. Blood-compatibility tests were also investigated. The water swelling ratio of the poly(HEMA-MAPA) beads increased significantly (68%) compared with pHEMA (55%). All the clotting times increased when compared with poly(HEMA) beads. Loss of platelets and leukocytes was very low. The maximum anti-LDL antibody attachment was achieved at pH 7.0. Attachment of anti-LDL antibody was 29.6 mg/g. There was a very low non-specific cholesterol binding onto the poly(HEMA-MAPA) beads, about 0.74 mg/g. Anti-LDL antibody attached beads adsorbed in the range of 13.3-16.0 mg cholesterol/g from hypercholesterolemic human plasma. Up to 92% of the adsorbed LDL was desorbed. The binding-elution cycle was repeated 10 times using the same beads. There was no significant loss of binding capacity.
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PMID:Immunoaffinity beads for selective removal of cholesterol from human plasma. 1280 43


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