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At least 271 records · Page 15Linked to original sources
PubMed1982

Complement activation by nylon- and polypropylene-looped prosthetic intraocular lenses.

Uncomplicated placement of an intraocular lens at the time of routine cataract extraction is associated with a greater inflammatory response than simple lens extraction. We have shown that certain components of prosthetic intraocular lenses are capable of activating the complement system in human serum in such a fashion as to generate peptides capable of mediating acute inflammatory reactions. Normal human serum was incubated with intraocular lenses in vitro and then examined for cleavage products of C3 and C5 and for C5-derived chemotactic activity for human polymorphonuclear leukocytes. Polymethylmethacrylate lenses with nylon and polypropylene loops were found to be capable of causing cleavage of C3 (detected by crossed immunoelectrophoresis) and C5 (detected by single-dimension radioimmunoelectrophoresis) as well as generation of C5-derived chemotactic activity in human serum. Serum incubated with polymethylmethacrylate lenses without loop supports exhibited no such activity. Results of our studies indicate that certain nylon- and polypropylene-looped intraocular lenses are not "inert" biologically and may elicit acute inflammatory reactions.

Autoradiography↗
PubMed1981

Platelets increase neutrophil adherence in vitro to nylon fiber.

The effect of platelets on the adherence of neutrophils to nylon fiber was assessed in whole blood samples and purified neutrophil suspensions in the presence or absence of plasma. In whole blood samples, increasing numbers of platelets were associated (r = 0.47, p less than 0.02) with increasing adherence of neutrophils. Addition of platelets in plasma to purified neutrophil suspensions increased (p less than 0.05) neutrophil adherence from 76.2% +/- 1.4 to 88.0% +/- 2.0. Similarly, addition of washed platelets without plasma also increased (p less than 0.05) neutrophil adherence from 67.9% +/- 5.8 (without added platelets) to 94.2% +/- 1.6 (with 300,000 platelets/mm3 added). In contrast, no augmentation of neutrophil adherence occurred if platelets had their aggregation response suppressed by pretreating platelet donors with aspirin. SEM supported these findings by showing platelets in close association with neutrophils adhering to nylon fiber. These findings emphasize the importance of platelet numbers and reactivity on the adherence of neutrophils.

Aspirin↗
PubMedDate not supplied

Intraoperative use of nylon bands in fracture fixation.

Nylon tie bands are introduced as an intraoperative aid in the application of internal fixation. Their use for holding metal plates on reduced fractures is advantageous over metal clamps in that they do not impede access to the fracture site, are easily applied, keep intraoperative injury to soft tissue at a minimum, and reduce manipulatory efforts at the fracture site, decreasing operating time. Scuffing of metal plates is eliminated. A technique for their use is described. Our experience with the nylon tie bands indicates that they are an effective adjunct, as opposed to conventional metal clamps, in open reduction and internal fixation of fractures in our institution.

Bone Plates↗
PubMedDate not supplied

Microbial retention characteristics of 0.2-microns-rated nylon membrane filters during filtration of high viscosity fluids at high differential pressure and varied temperatures.

Regulatory guidelines for aseptic manufacture of pharmaceuticals recommend validation of sterilizing filters by bacterial challenge under "worst case" conditions. The microbial retention characteristics of a sterilizing grade, 0.2-microns-rated Nylon 66 membrane filter were evaluated for filtration of high viscosity fluids. Glycerol (80%) was used as the carrier fluid and Pseudomonas diminuta ATCC 19146 as the challenge organism. Testing was carried out at a constant differential pressure of 60 psig over a six-hour test period. Test runs were undertaken at three different temperature conditions (25 +/- 5 degrees C, 42 +/- 1 degree C, and 50 +/- 1 degree C). Under the test conditions, the Nylon 66 membranes provided total retention of P. diminuta. The results demonstrated that a high pressure differential challenge using a high viscosity fluid over a six-hour test period at ambient and elevated temperatures did not alter the retention characteristics of the membrane filter.

Membranes, Artificial↗
PubMed1993

Immobilization of beta-glucosidase from Penicillium funiculosum on nylon powder.

beta-Glucosidase from Penicillium funiculosum was immobilized on nylon powder previously activated with triethyloxonium tetrafluoroborate, 1,2-diaminoethane and glutaraldehyde. The activation of the nylon powder and the immobilization processes were studied and optimized for the enzyme and the matrix. A high activity retention (67%) was obtained using the activation and immobilization conditions finally selected.

Borates↗
PubMed1993

Granny knot for interrupted 10-0 nylon sutures in cataract sections.

A granny knot instead of a reef (square) knot is advocated for 10-0 nylon interrupted sutures in limbal cataract sections, especially under a conjunctival flap. The second of the two throws is looped in the direction opposite to that in a reef knot so that the free ends lie at right angles to the plane of the suture. The second throw is used to "run down" the first to tighten the suture. To avoid postoperative erosion through conjunctiva, the ends are cut long with a blade while they lie flush with the sclera. The knot is locked when the traction required to tighten the suture is released and the thinned nylon recovers its original diameter on each side of the knot.

Cataract Extraction↗
PubMed1995

Skin closure using nylon and polydioxanone: a comparison of results.

Nylon vertical mattress sutures and interrupted subcuticular polydioxanone (PDS) sutures have been used for skin closure. The complications and cosmetic results of each have been noted in a prospective trial of 93 hip wounds. When nylon sutures are used there is an increased incidence of erythema and the final scar is less cosmetically attractive. Interrupted PDS sutures take longer to insert but have few complications and are recommended in both the young and elderly patients.

Adult↗
PubMedDate not supplied

The influence of some vegetable extracts on the in vitro adherence of mouse and human lymphocytes to nylon fibers.

We found that the total watery extracts obtained from roots of various plants such as Symphytum officinale, Phytolacca americana etc, precipitate human glycoproteins, agglutinate sheep red blood cells (SRBC) and stimulate lymphocyte adherence to nylon fibers. Five out of seven extracts precipitated human gammaglobulins and one of seven obviously agglutinate SRBC. If these cells were pretreated with rabbit antibodies against SRBC, all extracts agglutinated the cells at various degrees of intensity, the most active being Phytolacca americana. The adherence of mouse but not human lymphocytes to nylon fibers was stimulated by extracts of Symphytum officinale and Phytolacca americana. This process was neither stimulated nor inhibited by Mannose (Man), Galactose (Gal), Glucose (Glc), N-acethyl Galactose (GalNAc) and N-acethyl Glucose (Glc-NAc). These biological effects of the plant extracts could be the expression of a lectin-like ability to bind various sugars other than those mentioned. The results suggest the possibility of using different extracts as means to point out the presence in serum or at the cellular level of some carbohydrates influencing the cellular adhesion, phenomenon which plays an important role in the functions of hematopoietic cells.

Agglutination↗
PubMed1977

[Spontaneous rupture of nylon sutures in the cornea spontaneously (author's transl)].

In 8 patients rupture of nylon sutures in the cornea occurred spontaneously. This happened four times after a corneal cataract extraction, three times after a perforating keratoplasty and once after a perforating corneal injury. The rupture appeared three times 6 1/2 to 7 months after the operation, once after 1 1/2 months. In the other 4 cases the time of rupture is not known. The examination of the nylon sutures with a microscope showed a lamellar-concentric reduction in the straight parts of the sutures and superficial and deep sagittal in the curved parts of the sutures.

Cataract Extraction↗
PubMed2004

Complex morphology of melt-spun nylon-6 fibres investigated by 1H double-quantum-filtered NMR spin-diffusion experiments.

The complex morphology of high-speed melt-spun nylon-6 fibres hydrated with D2O was investigated using 1H double-quantum-filtered spin-diffusion NMR experiments. The magnetisation exchange from selected crystalline domains along the fibrils and interfibrils was simulated with the help of a three-dimensional solution of a spin-diffusion equation approximated by a product of one-dimensional analytical NMR signals, which correspond to a lamellar morphology. This allows to measure the sizes of crystalline and less-mobile amorphous domains along the fibrils, as well as the diameter of the fibrils and interfibril distances. A series of nylon-6 fibres with extreme values of winding speed and draw ratio was investigated. The changes detected in the domain size along the fibrils and interfibrils show the same trend in the data obtained from wide-angle X-ray diffraction and small-angle X-ray scattering.

Caprolactam↗
PubMed2001

Electrospray and matrix-assisted laser desorption/ionization mass spectral characterization of linear single nylon-6 oligomers.

Synthetic nylon-6 single molecular mass oligomers were studied by matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) mass spectrometry. These oligomers, considered as model compounds for the study of nylon-6 polymers, gave good mass spectrometric results using both MALDI and ESI. In spite of the gentle nature of both techniques, the MALDI and ESI spectra showed evidence of end-group cleavage from the oligomer chains. MALDI-MS was found to give similar fragmentation patterns for all of the oligomer samples. An increase in doubly charged ion signals with increasing oligomer mass was observed in the ESI mass spectra, as was end-group fragmentation. Signals from oligomer clusters were observed in ESI-MS for the dimer, tetramer and hexamer, most likely due to non-covalent bonding among the low-mass oligomer molecules.

Caprolactam↗
PubMed1997

Nylon-Based Affinity Membranes: Impacts of Surface Modification on Protein Adsorption.

Nylon microfiltration membranes were activated with bisoxirane and formaldehyde at terminal amino groups and amide groups of the nylon polymer, respectively. Dextrans were covalently immobilized on these activated membranes to yield dextran-coated membrane matrices. Both procedures led to a significant reduction of hemoglobin adsorption; however, bisoxirane activation required additional cross-linking of dextran and a second dextran layer to yield comparable quality of dextran-coated membranes than formaldehyde activation. Formaldehyde activation was easiest and cheapest and resulted in membranes with highest dextran density and relatively lowest nonspecific hemoglobin adsorption. Dextrans of &Mmacr;w >/= 40,000 were required for bisoxirane-activated membranes, whereas dextrans of &Mmacr;w = 6000 were sufficient for formaldehyde-activated membranes. Both activation methods resulted in stable coatings at low and high pH; however, formaldehyde-activated membranes were unstable under strongly acidic conditions at pH < 3. Dextran coils were found responsible for the reduction of the hydraulic permeability but also for the high ligand densities obtained after immobilization of Cibacron Blue F3G-A (360 nmol/cm2) and iminodiacetic acid (400 nmol/cm2). The thermodynamics of protein adsorption on dye ligand affinity (DLA) membranes corresponded with chromatographic sorbents and dye ligand conjugates, with the dextran coating demonstrating similar structure than dextrans in solution. Protein adsorption took place in the extended coil structure of dextrans with binding capacities up to 730 µg/cm2 lysozyme on DLA membranes and 470 µg/cm2 concanavalin A on metal chelate affinity membranes. Copyright 1997 Academic Press.

Journal Article↗
PubMed1984

Continuous-flow automated assay of steroids with nylon-tube-immobilized hydroxysteroid dehydrogenases.

Several NAD(P)+-dependent hydroxysteroid dehydrogenases, namely 3 alpha-hydroxysteroid dehydrogenase, beta-hydroxysteroid dehydrogenase, 7 alpha-hydroxysteroid dehydrogenase, and 12 alpha-hydroxysteroid dehydrogenase were separately immobilized on nylon tubes for the continuous-flow automated assay of hydroxysteroids. 3 alpha-Hydroxysteroid dehydrogenase was also immobilized on pore glass. Spectrophotometric monitoring in the visible region, where blank values were markedly reduced, was achieved through the Meldola blue catalyzed transfer of hydrogen from NAD(P)H to a tetrazolium salt. Nylon-tube-immobilized enzymes maintained 45-55% of the original activity after 1 month of intermittent use. The operational range, using the "end point" approach, was 1-25 nmol of steroid and the assay speed 10-15 samples/h. Reliable results were obtained in the determination of 3 alpha-hydroxysteroids and 3 beta, 17 beta-hydroxysteroids in urine and total bile acids in serum.

Autoanalysis↗
PubMed1989

Nick translation of DNA immobilized on nylon membranes.

Nick translation of DNA bound to nylon membranes is described. Phage lambda DNA was digested with restriction endonuclease HindIII. The fragments were separated by agarose electrophoresis and electrophoretically transferred to Zeta-Probe nylon membranes. After being air-dried, the areas with DNA fragments attached were cut out and subjected to nick translation. The labeled fragments, removed from the membranes by a single wash step, can be used as specific hybridization probes. Currently used methods require time-consuming electroelution and often additional purification procedures if a specific DNA fragment, separated by gel electrophoresis, is to be labeled by nick translation. With the procedure described it is possible to label many DNA fragments in parallel in a time- and cost-saving manner.

Autoradiography↗
PubMed1983

T-lymphocyte and B-lymphocyte dichotomy in anuran amphibians: I. T-lymphocyte proportions, distribution and ontogeny, as measured by E-rosetting, nylon wool adherence, postmetamorphic thymectomy, and non-specific esterase staining.

We used sheep erythrocyte (SRBC) E-rosetting, nylon wool fractionation thymectomy and nonspecific esterase staining to assess T-lymphocyte characteristics in Rana pipiens during various developmental stages. T-lymphocytes appear in the spleens of premetamorphic tadpoles. We found significant levels of lymphocytes classifiable as T-cells in the peripheral blood of adults, but fewer numbers of T-cells in the thymus, jugular bodies, spleen, pronephros, mesonephros, liver and bone marrow. In addition, thymectomized Xenopus laevis showed a sharp decrease in T-cells as evidenced by E-rosetting, ANAE stain and nylon wool fractionation. The presence of T-lymphocytes in anuran amphibians and the existence of a receptor for SRBC on a population of these cells, suggest conservation of T-cells during evolution.

Age Factors↗
PubMed2005

Adsorption of bilirubin with polylysine carrying chitosan-coated nylon affinity membranes.

Microporous polyamide membranes were activated by bisoxirane and subsequently bound with chitosan (CS) to amplify reactive groups. Then polylysine (PLL) as ligand was immobilized onto the CS-coated nylon membranes. The contents of CS and PLL of PLL-attached membranes were 93.2 and 90.4 mg/g nylon membrane, respectively. Such PLL-attached membranes were used to adsorb bilirubin from the bilirubin-phosphate solution and bilirubin-albumin solution. The adsorption mechanism of bilirubin and the effects of temperature, initial concentration of bilirubin, albumin concentration and ionic strength on adsorption were investigated by batch experiments. The results showed that the adsorption capacity increased with increasing the temperature while decreased with increasing the NaCl concentration and albumin concentration, and the adsorption isotherm fitted the Freundlich model well. The result of dynamic experiment showed PLL-attached membranes can well remove the bilirubin from the bilirubin-albumin solution.

Adsorption↗
PubMed2003

Trace-fiber color discrimination by electrospray ionization mass spectrometry: a tool for the analysis of dyes extracted from submillimeter nylon fibers.

The application of electrospray ionization mass spectrometry (ESI-MS) to trace-fiber color analysis is explored using acidic dyes commonly employed to color nylon-based fibers, as well as extracts from dyed nylon fibers. Qualitative information about constituent dyes and quantitative information about the relative amounts of those dyes present on a single fiber become readily available using this technique. Sample requirements for establishing the color identity of different samples (i.e., comparative trace-fiber analysis) are shown to be submillimeter. Absolute verification of dye mixture identity (beyond the comparison of molecular weights derived from ESI-MS) can be obtained by expanding the technique to include tandem mass spectrometry (ESI-MS/MS). For dyes of unknown origin, the ESI-MS/MS analyses may offer insights into the chemical structure of the compound-information not available from chromatographic techniques alone. This research demonstrates that ESI-MS is viable as a sensitive technique for distinguishing dye constituents extracted from a minute amount of trace-fiber evidence. A protocol is suggested to establish/refute the proposition that two fibers--one of which is available in minute quantity only--are of the same origin.

Journal Article↗
PubMed2006

Chemical engineering of the single-walled carbon nanotube-nylon 6 interface.

We report an approach to the chemical engineering of the single-walled carbon nanotube (SWNT)-polymer interfacial interaction in a nylon 6 graft copolymer composite which is based on the degree of SWNT functionality. Continuous fibers are drawn from composites fabricated from the in situ polymerization of caprolactam with SWNTs possessing a range of carboxylic acid (SWNT-COOH) and amide (SWNT-CONH(2)) functionalities. Mechanical performance evaluation of the composite fibers shows that a high concentration of the carboxylic acid functional groups leads to a stronger SWNT-nylon interfacial interaction, as reflected in greater values of the Young's modulus and mechanical strength. Replacement of the COOH group by CONH(2) in the SWNT starting material changes the grafting polymerization chemistry, thereby leading to the covalent attachment of longer graft copolymer chains to the SWNTs, and alters the composite morphology while increasing the composite flexibility and toughness.

Journal Article↗