Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Contact lens related Acanthamoeba keratitis has been more often associated with the use of soft contact lenses than with the use of rigid gas permeable (RGP) contact lenses. We studied the adherence of Acanthamoeba cysts and trophozoites to unworn RGP (silicone acrylate and fluoropolymer) and low and high water content soft contact lenses marketed in India. A human corneal isolate of Acanthamoeba polyphaga suspended in saline (1 x 10(5) amoebae/mL) was used. Lens segments were exposed to A. polyphaga cysts or trophozoites with or without shaking. After exposure for zero to 7 hours, lenses were either washed or not washed and the adherence was determined using light microscopy and a hemocytometer (per square millimeter of the lens). Both cysts and trophozoites immediately adhered to all four types of lenses. Adhesion increased with an increase in exposure time. The number of adherent cysts and trophozoites was higher (P = 0.043-0.0003) in the unwashed group of lenses at all exposure times for all lenses. Among washed groups, adherence was greatest with RGP silicone acrylate and high water content soft lenses. Trophozoites of Acanthamoeba showed greater adherence to RGP lenses, whereas cysts showed greater adherence to high water content soft lenses. Shaking did not have a significant effect on adherence. Adhesion of Acanthamoeba to contact lenses may play an important role in the pathogenesis of Acanthamoeba keratitis.
 ...
PMID:Adherence of cysts and trophozoites of Acanthamoeba to unworn rigid gas permeable and soft contact lenses. 856 94

Adhesion of xerogel dressings prepared on Eudragit (E), methylcellulose (MC) and glycerol compositions, remaining within the range of 625-650 g, after addition polyvinylpyrolidone (PVP) amounts to 450-1250 g. Dissolution time from xerogel dressings without PVP additive both in water and in an artificial gastric juice amounts to 3 h. Addition of PVP results in reduction of the elution rate. In dependence upon the PVP/E/MC ratio elution time amounts to 3-3.5 h. Pharmaceutical availability of the Kunitz protease inhibitor in particular groups of then dressings depends upon concentration of hydrophilizing agent. The semi-liberation times amounts to 3.65-17.50 h.
 ...
PMID:Studies on dressings for mucosa of the oral cavity. Part 3: Effect of preparation technology on the physical and chemical properties of stomatological xerogel dressings. 862 40

To investigate in vitro platelet adhesion to hydrogels, using electron-beam irradiation, polymer reaction, and radical polymerization, hydrogels were synthesized to have a wide range of water content. The nonionic synthesized hydrogels include polyacrylamide (PAAm), poly(vinyl alcohol) (PVA), poly(ethylene glycol) (PEG), poly(N-vinyl pyrrolidone), and poly(methoxy-PEG methacrylate) while the ionic hydrogels were crosslinked poly(AAm-acrylic acid) and poly(AAm-dimethylaminoethyl methacrylate) copolymers. Adhesion of washed rabbit platelets to these hydrogels were studied in phosphate-buffered saline for 30 min. In the case of PVA and PAAm hydrogels, platelet adhesion also was conducted in the presence of proteins. The protein sorption into PVA hydrogel was studied by fluorescent spectroscopy. It was found that all the nonionic hydrogels exhibited a lower level of platelet adhesion than did conventional hydrophobic polymers, such as medical-grade poly(vinyl chloride), polyurethane, and silicone, and they exhibited the minimum platelet adhesion at a water content of around 90%. PAAm and PEG hydrogels had the weakest interaction with platelets when the water content was lower than 90%. PVA hydrogel showed the highest platelet adhesion in the low-water-content region, but the platelet adhesion was greatly reduced in the presence of proteins. Significant protein sorption was noted when the water content of PVA hydrogel was as high as 80%. Introduction of a positive charge into the PAAm hydrogel promoted platelet adhesion whereas the negative charge introduced into the hydrogel slightly reduced the number of adhered platelets.
 ...
PMID:In vitro platelet adhesion to nonionic and ionic hydrogels with different water contents. 869 92

Pycnidiospores of Phyllosticta ampelicida, the causal agent of black rot of grape, were found to germinate only on substrata on which they were firmly attached. Such surfaces were poorly wettable and had advancing contact angles (straight thetaa) formed by a water drop of >80&deg;, e.g., grape leaf, polystyrene, Teflon, polycarbonate, collodion, and glass treated with the silanes n-octadecyltrichlorosilane, dimethyldichlorosilane, or diphenyldichlorosilane. When pycnidiospores were deposited on more wettable surfaces they did not attach firmly and did not germinate. Such highly wettable surfaces had straight thetaa </= 40&deg; and were represented by heat-treated glass, cellophane, nutrient- and water-agars, polystyrene treated with UV-irradiation or sulfuric acid, and glass silanized with n-2-aminoethyl-3-aminopropyltrimethoxysilane, n-(trimethoxysilylpropyl)ethylenediamine triacetic acid trisodium, or 3-aminopropyltriethoxysilane. Adhesion of pycnidiospores was assessed with and without a hydraulic shearing force. Pycnidiospore adhesion occurred over several minutes in distilled deionized water, unless it was first acidified, which decreased attachment time to <0.03 s. Attachment of pycnidiospores treated with sodium azide, formaldehyde, or boiled in water for 10 min was similar to nontreated conidia. Possible mechanisms of adhesion of the conidia to surfaces include hydrophobic and ionic interactions.
 ...
PMID:Germination of Phyllosticta ampelicidaPycnidiospores: Prerequisite of Adhesion to the Substratum and the Relationship of Substratum Wettability 881 83

Coating uroepithelial cells or catheter materials with lactobacilli has been shown to retard the development of a uropathogenic biofilm, with biosurfactant production and strong adhesion being two prerequisite properties of the Lactobacillus strains to be employed. In this paper, adhesion of six selected Lactobacillus strains to silicone rubber and glass in urine and in a phosphate buffer was studied using a parallel plate flow chamber. In addition, adhesive cell surface properties of the lactobacilli, i.e. the pH dependences of their zeta potentials and their hydrophobicities by water contact angles, were determined. L. acidophilus ATCC 4356 and L. fermentum B54 were the only strains showing significant adhesion to both hydrophobic silicone rubber and hydrophilic glass, possibly by virtue of their high cell surface hydrophobicities (water contact angles of 68 and 75 degrees, respectively) and small zeta potentials (-10.0 and -8.1 mV in buffer, respectively). Both hydrophobic Lactobacillus strains adhered less well in urine than in buffer. The remaining Lactobacillus strains studied were hydrophilic, with water contact angles between 25 and 36 degrees, and had highly negative zeta potentials, reaching -37.7 mV in buffer. Adhesion of these highly negatively charged, hydrophilic strains in buffer was essentially absent, while for some of these strains minor adhesion in urine was observed. This study demonstrates that the adhesion of lactobacilli to substrata differs with strain hydrophobicity and charge, and that urinary components can affect the ability of hydrophilic Lactobacillus strains to adhere to substrata.
 ...
PMID:Adhesion of Lactobacillus species in urine and phosphate buffer to silicone rubber and glass under flow. 900 3

Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of silicone rubber voice prostheses. In this paper, adhesion of two streptococcal, staphylococcal, Candida albicans and Candida tropicalis strains, isolated from explanted voice prostheses was investigated to silicone rubber with and without a salivary conditioning film in a parallel-plate flow chamber. Within each microbial pair of one species, the strain with the most negative zeta potential adhered most slowly to negatively charged silicone rubber. No other clear relationships were obvious between adhesion to silicone rubber and microbial zeta potentials of cell-surface hydrophobicities, as by water contact angles. A 1.5-h adsorbed salivary conditioning film appeared to possess components, presumably albumin and lysozyme, slowing down the deposition of the yeasts and some of the streptococcal and staphylococcal isolates. In addition, microbial adhesion in a stationary end point was generally lower to silicone rubber with an adsorbed salivary conditioning film than without one. Nearly all microorganisms adhering to an adsorbed salivary conditioning film, yeasts as well as bacteria, were stimulated to detach by the passage of an air bubble through the chamber, but microorganisms adhering directly to the silicone rubber, especially C tropicalis strains, detached in far lower numbers under the influence of a passing air bubble. The present observations are in agreement with clinical in vivo findings that in patients with reduced saliva production after radiotherapy, the device life of the voice prosthesis is significantly shortened and suggests that isolated salivary components might be used as an anti-adhesive.
 ...
PMID:Adhesion to silicone rubber of yeasts and bacteria isolated from voice prostheses: influence of salivary conditioning films. 902

The adhesion of platelets to a series of segmented polyurethanes having sulfonate groups in the hard segment is reported. The polyurethanes were synthesized using sulfonated chain extenders of different structure. Analogous control materials without sulfonate groups also were studied. Adhesion was measured in vitro using washed human platelets in a carrier fluid consisting of Tyrode's buffer with apyrase, albumin, and red cells at normal concentration. The polymers were characterized by gel permeation chromatography and elemental analysis. Water absorption and thermal transitions also were determined. It was found that the sulfonated materials absorb significant amounts of water while the nonsulfonated analogs do not. The surfaces of polymer films were characterized by water contact angle and XPS. The contact angles of the sulfonated surfaces were relatively low. Platelet adhesion to the sulfonated polymers was found to be very high compared to the nonsulfonate analogs. The local environment of the sulfonate groups (different chain extenders) also appears to have an effect on platelet interactions. Albumin adsorption was high on all the materials and was not correlated with platelet adhesion. It appears from this work that platelets may have a binding site that is specific for sulfonate groups.
 ...
PMID:Physicochemical properties and platelet interactions of segmented polyurethanes containing sulfonate groups in the hard segment. 905 28

Adhesion of xerogel dressings prepared on Eudragit-E 100, methylcellulose and glycerol compositions in acetone/water mixtures, remains within the range of 317-967 g, after addition of polyvinylpyrrolidone (PVP), it increases to 633-1200 g. Dissolution time of dressings in water amounts to 6 h, in artificial gastric juice to 3 h. Addition of PVP results in decrease of the elution rate, dissolution time amounts to 2.5 h. The Kunitz protease inhibitor semi-liberation times amount to 3.3-7.6 h.
 ...
PMID:Studies on dressings for mucosa of the oral cavity. Part 4: Influence of technology used in the preparation of dental xerogel dressings in the presence of acetone on their properties. 967 69

Adhesion of 4-META to Au-In alloy was improved by adding In equivalent to .15% of Au content. On the basis of the results of Au-In alloys analyzed by XPS, the present study investigated the reason why adhesion of the Au-In alloy was improved. The O 1s spectrum could be separated into three oxygen chemical states, In2O3, chemisorbed H2O, and physisorbed H2O. The amount of chemisorbed H2O decreased remarkably with increasing amount of In. It is considered that the poor adhesive ability of the pure gold and alloys containing only small amounts of In was due to the chemisorbed H2O molecules and insufficient indium oxide on the alloy surface. It was established that excellent adhesion requires an oxide with chemical affinity for 4-META to cover at least 50% of the alloy surface.
 ...
PMID:Adhesion of adhesive resin to dental precious metal alloys. Part II. The relationship between surface structure of Au-In alloys and adhesive ability with 4-META resin. 1021 42

Initial adhesion of fungi to plasticized polyvinyl chloride (pPVC) may determine subsequent colonization and biodeterioration processes. The deteriogenic fungus Aureobasidium pullulans was used to investigate the physicochemical nature of adhesion to both unplasticized PVC (uPVC) and pPVC containing the plasticizers dioctyl phthalate (DOP) and dioctyl adipate (DOA). A quantitative adhesion assay using image analysis identified fundamental differences in the mechanism of adhesion of A. pullulans blastospores to these substrata. Adhesion to pPVC was greater than that to uPVC by a maximum of 280% after a 4-h incubation with 10(8) blastospores ml(-1). That plasticizers enhance adhesion to PVC was confirmed by incorporating a dispersion of both DOA and DOP into the blastospore suspension. Adhesion to uPVC was increased by up to 308% in the presence of the dispersed plasticizers. Hydrophobic interactions were found to dominate adhesion to uPVC because (i) a strong positive correlation was observed between substratum hydrophobicity (measured by using a dynamic contact angle analyzer) and adhesion to a range of unplasticized polymers including uPVC, and (ii) neither the pH nor the electrolyte concentration of the suspension buffer, both of which influence electrostatic interactions, affected adhesion to uPVC. In contrast, adhesion to pPVC is principally controlled by electrostatic interactions. Enhanced adhesion to pPVC occurred despite a relative reduction of 13 degrees in the water contact angle of pPVC compared to that of uPVC. Furthermore, adhesion to pPVC was strongly dependent on both the pH and electrolyte concentration of the suspension medium, reaching maximum levels at pH 8 and with an electrolyte concentration of 10 mM NaCl. Plasticization with DOP and DOA therefore increases adhesion of A. pullulans blastospores to pPVC through an interaction mediated by electrostatic forces.
 ...
PMID:Plasticizers increase adhesion of the deteriogenic fungus Aureobasidium pullulans to polyvinyl chloride. 1042 51


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>