Showing papers on "Glutaraldehyde published in 1992"
TL;DR: In this article, a blend membrane consisting of polyvinyl alcohol (PVA) and chitosan was prepared from a solvent-casting technique and characterized for their intermolecular interactions using infrared and X-ray diffraction methods.
Abstract: Blend membrane consisting of poly(vinyl alcohol) (PVA) and chitosan was prepared from a solvent-casting technique and characterized for their intermolecular interactions using infrared and X-ray diffraction methods. Cross-linking the blend with glutaraldehyde produces a membrane with lower crystallinity and a smaller swelling degree, but having improved thermostability and mechanical properties. The present blend membrane shows a pH-dependent swelling characteristic and will be discussed in detail. © 1992 John Wiley & Sons, Inc.
186 citations
TL;DR: Information gaps concerning the actions of glutaraldehyde have been identified in this review and recommendations are suggested for additional short- and long-term studies.
Abstract: Glutaraldehyde, a low molecular weight aldehyde, has been investigated for toxicity in humans and animals. Examination of this dialdehyde was indicated from previous studies with other aldehydes in which carcinogenicity of formaldehyde and toxicity of acetaldehyde and malonaldehyde have been disclosed. Information gaps concerning the actions of glutaraldehyde have been identified in this review and recommendations are suggested for additional short- and long-term studies. In particular, information regarding irritation of the respiratory tract, potential neurotoxicity, and developmental effects would assist in a complete hazard evaluation of glutaraldehyde. Further study related to disposition, metabolism, and reactions of glutaraldehyde may elucidate the mechanism of action.
177 citations
TL;DR: Glutaraldehyde was almost as potent as formaldehyde, indicating that the bifunctional nature of this 5-carbon saturated aldehyde may be crucial to its high efficiency of DNA-protein crosslinking.
Abstract: Using a filter-binding assay based on precipitation of pUC13 plasmid DNA bound to calf-thymus histones, we have determined the efficiency of formation of DNA-protein crosslink formation induced by several aldehyde compounds in vitro. Formaldehyde, glutaraldehyde and acrolein were the most potent, causing 1 crosslink per 2.7 kbp of DNA at 1.5, 8 and 150 microM, respectively. All other compounds tested gave 1 crosslink per plasmid molecule in the mM concentration range as follows: acetaldehyde, 115 mM; propionaldehyde, 295 mM; butyraldehyde, 360 mM; crotonaldehyde, 8.5 mM; trans-2-pentenal, 6.3 mM. Significant decreases in the efficiency of DPXL formation were observed with monofunctional aldehydes of higher carbon chain length. For example, the concentration of formaldehyde needed to give 1 crosslink per molecule was almost 10(5) times less than that of acetaldehyde. Acetaldehyde differs from formaldehyde only by one saturated carbon. The presence of an unsaturated bond between the 2-3 carbons improved the potential for crosslink formation. For example, acrolein was over 500-fold more potent than propionaldehyde. Glutaraldehyde was almost as potent as formaldehyde, indicating that the bifunctional nature of this 5-carbon saturated aldehyde may be crucial to its high efficiency of DNA-protein crosslinking.
116 citations
TL;DR: The structure of GA was investigated with uv absorption and light scattering to avoid problems in the experiments and it was discovered that 70% glutaraldehyde solution contains a large quantity of polymeric species with cyclic hemiacetal structure.
78 citations
TL;DR: Rat erythrocytes loaded with metronidazole by a method based on hypotonic preswelling, hemolysis, isotonic resealing and reannealing and glutaraldehyde treatment resulted in the stabilization of loaded cells, which were found to be highly resistant to the osmotic and turbulence shocks.
Abstract: Rat erythrocytes were loaded with metronidazole by a method based on hypotonic preswelling, hemolysis, isotonic resealing and reannealing. The encapsulation efficiency of 42-56% was achieved. The loaded cells exhibited elevated osmotic fragility and lower resistance to turbulence shock as compared to the normal cells and were found to release encapsulated drug slowly. The glutaraldehyde treatment of the cells resulted in the stabilization of loaded cells, which were found to be highly resistant to the osmotic and turbulence shocks. In-vitro release of metronidazole was also retarded upon treatment, and was dependent upon the concentration of glutaraldehyde. The loaded erythrocytes were obtained in powder form, ready for reconstitution, with a view to improve the shelf life. On the basis of in-vitro studies glutaraldehyde treated erythrocytes appeared to be promising carriers of metronidazole.
51 citations
TL;DR: In this paper, a blend membrane consisting of polyvinyl alcohol (PVA) and chitosan was prepared from solvent casting technique for effective separation of ethanol-water mixture by pervaporation.
Abstract: Blend membrane consisting of poly(vinyl alcohol)(PVA) and chitosan was prepared from solvent casting technique for effective separation of ethanol-water mixture by pervaporation. Selectivity toward water and the flux through the blend membrane, crosslinked with glutaraldehyde at the concention of 4×10-6 mol/g, were∼450 and 0.47 kg/m2.hr, respectively.
48 citations
TL;DR: Urease enzyme was immobilized in photographic gelatin by chemical cross-linking using formaldehyde, glutaraldehyde and chromium (III) acetate to study effects of enzyme and cross-linker concentrations, temperature, incubation time and pH on urea hydrolysis.
45 citations
TL;DR: It is concluded that tobramycin and vancomycin accumulate in lysosomes of proximal tubular cells throughout 10 days of treatment and that vancomYcin has no effect on the subcellular distribution of tobramYcin.
Abstract: The subcellular localization of tobramycin and vancomycin in the renal cortices of rats was determined with ultrathin sections by immunogold labeling. Four groups of four rats each were treated for 10 days with saline (NaCl, 0.9%), tobramycin at dosages of 20 mg/kg of body weight per 12 h intraperitoneally, vancomycin at dosages of 25 mg/kg/12 h subcutaneously, or the combination tobramycin-vancomycin. On day 11, the animals were killed, and cubes of renal cortex were fixed overnight in phosphate-buffered glutaraldehyde (0.5%), dehydrated in ethanol, and embedded in Araldite 502 resin. Ultrathin sections were made and incubated with sheep antitobramycin antibody followed by protein A-gold (15-nm diameter) complex or rabbit antivancomycin antibody followed by gold (30-nm diameter)-labeled goat anti-rabbit antibody. For the double labeling, incubations were made on opposite sides of the grid. Tobramycin was detected over the lysosomes of proximal tubular cells, but the labeling was concentrated into small areas in the matrix of the lysosomes. Vancomycin was seen over the lysosomes of proximal tubular cells and was distributed uniformly throughout the matrix of the lysosomes. In rats treated with tobramycin-vancomycin, both drugs were still detected in lysosomes of proximal tubular cells. It is concluded that tobramycin and vancomycin accumulate in lysosomes of proximal tubular cells throughout 10 days of treatment and that vancomycin has no effect on the subcellular distribution of tobramycin.
41 citations
TL;DR: Pretreatment of pericardium with iron (III) citrate reduced calcification in the rat subcutaneous implant model, as did acyl azide activation of carboxyl and amide groups, but glutaraldehyde post-fixation had no significant relationship to the calcification rate.
40 citations
Journal Article•
TL;DR: In vitro endothelial cell proliferation rate was impaired dose-dependently in the presence of increasing glutaraldehyde concentrations of the cultivation medium, and Cultivation of endothelial cells was impossible on the surface of commercially available BHV material, but successful and uninhibited when toxic glutarhyde ligands of the BHv material were antagonized by treatment with L-glutamic acid.
38 citations
TL;DR: Neither microwave irradiation by itself, Cialit or ethyl alcohol induce cross-linking of collagen fibres in dermal sheep collagen, and these findings are relevant for implant studies.
TL;DR: Culture conditions which facilitate the growth of stable, non-proliferating, human umbilical vein endothelial cell (HUVEC) monolayers are studied and a cobblestone appearance could be achieved if glutaraldehyde cross-linked gelatin coatings on glass were used as substrates.
Abstract: We have studied culture conditions which facilitate the growth of stable, non-proliferating, human umbilical vein endothelial cell (HUVEC) monolayers. Gelatin and fibronectin coatings, with or without glutaraldehyde cross-linking, on both plastic and glass were investigated for initial attachment of HUVEC and growth characteristics. The presence during culture of intercellular (IC) junctions demonstrated by silver staining, expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) and maintenance of a cobblestone appearance of HUVEC monolayers were assessed over time. Glutaraldehyde cross-linked fibronectin and gelatin coatings on glass and glutaraldehyde cross-linked gelatin or untreated fibronectin coatings on plastic served as good substrates for short term culture. Long term (20 days) cultures of HUVEC which maintained silver and PECAM-1 staining of IC junctions and a cobblestone appearance could be achieved if glutaraldehyde cross-linked gelatin coatings on glass were used as substrates.
TL;DR: The studies suggest the potentiality of primaquine-loaded, glutaraldehyde-treated erythrocytes as an intravenous drug delivery system for casual prophylaxis and radical cure of malaria.
Abstract: Primaquine phosphate, an antimalarial drug, was loaded in erythrocytes by the process of endocytosis. The encapsulation of 0.1-0.15 mg of drug ml−1 of packed erythrocytes was achieved. The loaded cells attained spherical shape and exhibited higher osmotic fragility and lower resistance to turbulence shock as compared with normal cells. Glutaraldehyde treatment stabilized the cells which were noted to be resistant to the osmotic and turbulence shocks. In vitro release of drug and haemoglobin was also retarded upon treatment of loaded erythrocytes with glutaraldehyde. The studies suggest the potentiality of primaquine-loaded, glutaral-dehyde-treated erythrocytes as an intravenous drug delivery system for casual prophylaxis and radical cure of malaria.
TL;DR: Two methods of sample preparation, originally developed for transmission electron microscopy and better at preserving bacterial exopolymers than the traditional fixation with glutaraldehyde, were adapted for scanning electron microscope and found to improve considerably the preservation of exopolymer secreted by three bacterial strains.
Abstract: SUMMARY
Two methods of sample preparation, originally developed for transmission electron microscopy and better at preserving bacterial exopolymers than the traditional fixation with glutaraldehyde, were adapted for scanning electron microscopy. The first involves a glutaraldehyde-lysine mixture as a fixative. The second, based on the use of polycationic ferritin, was modified to include a post-fixation step with either glutaraldehyde or a glutaraldehyde-lysine mixture. These techniques were found to improve considerably the preservation of exopolymers secreted by three bacterial strains.
TL;DR: An amperometric biosensor has been developed for monitoring glutamine in the pulsed-batch cultivation of murine hybridoma cells and the data obtained agreed well with those high-performance liquid chromatography, thus validating the applicability of the biosensor.
TL;DR: Examinations of thin sections showed that microwave fixation (glutaraldehyde or sequential aldehyde/osmium) is an attractive and rapid alternative method for processing plant tissues for electron microscopy.
Abstract: Microwave-enhanced fixation of animal tissues for electron microscopy has gained in interest in recent years. Attempts to use microwave irradiation for the preparation of plant tissues are rare. In this study; I report on microwave conditions which allow a high quality preservation of plant cell structure. Tissues used were: internodes of Chara vulgaris, leaves of Hordeum vulgare, root tips of Lepidium sativum. Microwave irradiation was done with a commercial microwave oven (Sharp R-5975). Fixatives used were: 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2 and 1% osmium tetroxide in veronal/acetate buffer, pH 7.2. Conventional fixations with glutaraldehyde/osmium were compared with microwave fixations. Examinations of thin sections showed that microwave fixation (glutaraldehyde or sequential aldehyde/osmium) is an attractive and rapid alternative method for processing plant tissues for electron microscopy. The optimal conditions found were: microwave oven at power level 50 W, 6.5 ml of fixative solution, irradiation times between 32-34 s, final temperature between 40 degrees C and 47 degrees C.
TL;DR: The immobilized whole cells showed enhanced hydrolysis rates in the conversion of benzylpenicillin to 6-aminopenicillanic acid (6-APA) compared to untreated cells immobilized and used under identical conditions.
Journal Article•
TL;DR: Limited exposure to aldehydes after glycerol treatment inhibits endothelial growth, but this effect was ameliorated by prolonged implantation, and the possibility of host endothelium-covered, noncalcifying bioprostheses is now real.
Abstract: Background. Neither homografts nor bioprostheses have previously been seen to acquire a host endothelium. We previously reported a direct relation between aldehyde tanning and bioprosthesis calcification and the absence of calcification in the absence of aldehyde. Methods and Results. Bovine pericardium was 1) treated with 0.625% glutaraldehyde and stored in 4% formaldehyde, 2) treated with 99.5% glycerol, and 3) treated with 99.5% glycerol and stored in formaldehyde (0.25-4%)
TL;DR: The results suggest that glutaraldehyde selectively couples the amino terminus of the peptide to the carrier protein, while carbodiimide coupling produces a mixture of specificities, and support the idea that optimal immunohistochemical demonstration of small molecules is obtained when the coupling agent is included in the fixative to induce the actual coupling reaction during fixation.
Abstract: For immunohistochemical demonstration of the enkephalin octapeptide Met5-enkephalin-Arg6-Gly7-Leu8, the peptide was conjugated with a carrier protein using either glutaraldehyde or 1-ethyl-3 (3-dimethylaminopropyl)-carbodiimide as coupling agent. Antisera were raised in rabbits and their specificity was studied using the immunoblotting technique. The results suggest that glutaraldehyde selectively couples the amino terminus of the peptide to the carrier protein, while carbodiimide coupling produces a mixture of specificities. Accordingly, antiserum raised against the glutaraldehyde-induced conjugate specifically recognized the peptide carboxyl terminus and allowed immunohistochemical distinction of the octapeptide from other closely related opioid peptides, such as Leu5- and Met5-enkephalin, Met5-enkephalin-Arg6-Phe7, and Phe1-Met2-Arg3-Phe4-NH2. In contrast, antiserum raised against the carbodiimide-induced octapeptide conjugate showed a mixture of specificities. Addition of glutaraldehyde to the fixative enhanced octapeptide immunoreactivity in several tissues and revealed a previously unknown nerve system in the pituitary gland. These results support the idea that optimal immunohistochemical demonstration of small molecules, which requires conjugation to a carrier protein, is obtained when the coupling agent is included in the fixative so as to induce the actual coupling reaction during fixation.
TL;DR: The experiments showed that cytoplasmic morphology was best preserved after vapor fixation in p‐formaldehyde, and this fixation also led to the highest degree of specific antibody binding.
Abstract: In order to find a good compromise between preservation of ultrastructural morphology and retention of antigenicity, birch pollen grains were chemically fixed in aqueous p-formaldehyde or glutaraldehyde, in p-formaldehyde or glutaraldehyde dissolved in anhydrous glycerol, and in p-formaldehyde or glutaraldehyde vapor. Representative cytoplasmic areas were inspected for the preservation of ultrastructural morphology and for their capacity to bind a monoclonal antibody against Bet v I, the major birch pollen allergen. The experiments showed that cytoplasmic morphology was best preserved after vapor fixation in p-formaldehyde. This fixation also led to the highest degree of specific antibody binding.
TL;DR: In this article, a crosslinked pullulan polysaccharide was crosslinked with glutaraldehyde for use as a separation membrane for aqueous alcohol solutions for pervapouration and evapomeation.
TL;DR: It was found that the conformational changes of the active site of papain upon immobilization were in agreement with the enzymatic properties of the enzyme.
01 Jan 1992
TL;DR: The aim of further modification of HbNFPLP was to achieve a retention time of about 24 hours and to determine the optimal degree of polymerization with respect to the effects on vascular retention time, oncotic activity, viscosity and oxygen affinity.
Abstract: In 1982 we synthesized 2-Nor-2-formylpyridoxal 5′-phosphate (NFPLP) and subsequently showed that coupling of the s chains of hemoglobin (Hb) by this organic phosphate compound according to Benesch et al. (1) lowers the oxygen affinity and prolongs the retention time in the circulation of rats and rabbits with a factor 3 by prevention of excretion via the kidneys. Optimal conditions for the purification of HbNFPLP either by ion-exchange chromatography or by heat treatment were established with recoveries of 70% and 85%, respectively. By extrapolation from the data in rats and rabbits a half life of about 8 hours can be expected in the circulation of humans. However, under some conditions a further prolongation is required.The aim of further modification of HbNFPLP was to achieve a retention time of about 24 hours. Polymerization with glutaraldehyde to polyHbNFPLP resulted in a mixture of polymers of different size. We determined the optimal degree of polymerization with respect to the effects on vascular r...
TL;DR: The molecular weight of the samples, the amino acid compositions, the cross-linking agent used, the molar ratios between cross- linking agents and functional residues and system pH were found to have roles in the insolubilizing reaction and the gel formation.
Patent•
08 Jul 1992TL;DR: In this article, a charge composition containing aqueous mixtures of organic nitrogen compounds may be separated by pervaporation through a membrane assembly containing a porous ceramic support bearing as separating layer, polyvinyl alcohol which has been cross-linked as with glutaraldehyde.
Abstract: Charge compositions containing aqueous mixtures of organic nitrogen compounds may be separated by pervaporation through a membrane assembly containing a porous ceramic support bearing as separating layer, polyvinyl alcohol which has been cross-linked as with glutaraldehyde.
TL;DR: In this paper, the authors studied the adaption time curves from finite baths for untreated cotton fabric and cottons treated with differing molecular chain lengths of aldehydes (formaldehyde and glutaraldehyde).
Abstract: Adsorption time curves from finite baths have been studied for untreated cotton fabric and cottons treated with differing molecular chain lengths of aldehydes (formaldehyde and glutaraldehyde). Crosslinking reduced the rate constant, structural diffusion resistance constant, and equilibrium adsorption of dyeing. Additionally, these data decreased with increasing agent concentration and with increasing molecular chain length of the crosslinking agent. The dyeing activation energy of the glutaraldehyde treated fabric was lower than that of the formaldehyde treated fabric.
TL;DR: The literature review cites adverse health effects experienced by workers exposed to glutaraldehyde, a chemical commonly used in endoscopy units, and recommendations for reducing exposure to glutARaldehyde in endoscope units are included.
Abstract: This article discusses the potential toxicity of glutaraldehyde, a chemical commonly used in endoscopy units. The literature review cites adverse health effects experienced by workers exposed to glutaraldehyde. The sampling methodology for glutaraldehyde relative to the Occupational Safety and Health standard for glutaraldehyde is presented. Air monitoring should be performed to assess employee exposure to airborne glutaraldehyde in endoscopy departments. Recommendations for reducing exposure to glutaraldehyde in endoscopy units are included.
TL;DR: Amidolytic activity using the specific chromogenic substrate for urokinase, S-2444, showed that enzyme activity could be retained during this glutaraldehyde cross-linking and immobilization of albumin microspheres.
Abstract: A method of immobilizing urokinase on albumin microspheres has been developed. Laser scattering, which was used to follow particle size from the initial emulsification stage to the final aqueous resuspension of the microsphere stage, showed that particle coalescence and crosslinking were critical parameters in manufacturing the microspheres. Chemical dehydration with 2,2-dimethoxypropane was used to convert an albumin emulsion into an albumin suspension and to reduce coalescence. An optimal amount of dehydrant produced 0.3-µm particles which resisted a 50°C temperature challenge. Since oil/glutaraldehyde emulsion resulted in large particles with no urokinase activity, the cross-linking concentration of glutaraldehyde was reduced by solubilizing 25% (w/v) glutaraldehyde in the oil phase with n-propanol. A concentration of 0.015% (v/v) glutaraldehyde effectively immobilized urokinase and stabilized albumin microspheres. Amidolytic activity using the specific chromogenic substrate for urokinase, S-2444, showed that enzyme activity could be retained during this glutaraldehyde cross-linking.
TL;DR: The results show that the exine of caveate pollen has a large capacity for holding lipid, and a simple method for the detection of lipoidal substances on the pollen surface, in bacular interstices, and within the caveae is used.
Abstract: After fixation of mature pollen of Solidago canadensis in osmium tetroxide evidence for lipids on and in the exine and in the cytoplasm was similar to what can be seen with the light microscope in fresh pollen, whereas there was relatively little evidence for lipids after glutaraldehyde fixation or the common method using glutaraldehyde followed by osmium tetroxide. We have used a simple method for the detection of lipoidal substances on the pollen surface, in bacular interstices, and within the caveae. Our results show that the exine of caveate pollen has a large capacity for holding lipid. Cavea were lost (deflated) unless we exposed anthers to osmium tetroxide prior to methods which resulted in extraction of lipoidal materials; such methods included glutaraldehyde fixation followed by washing in buffer prior to osmium tetroxide.
TL;DR: It is concluded that monosodium glutamate couples with residual aldehyde, which significantly reduces calcification of glutaraldehyde fixed porcine aortic valves while preserving a higher tissue collagen and water content after implantation.
Abstract: The use of bioprosthetic valves remains limited due to poor long-term durability primarily because of tissue calcification-associated degeneration. Release of locally cytotoxic residual aldehyde after glutaraldehyde fixation is one of the major causes of this degeneration. In this study, monosodium glutamate was used as postfixation treatment to bind residual aldehyde in order to block its toxic effects. Thirty-six pieces of fresh porcine aortic valves were fixed by 0.625% glutaraldehyde for 14 days, and then 18 of them were treated with 1% monosodium glutamate for another 3 days before they were implanted subcutaneously into the backs of two groups of rats (n = 9 in each group) for 45 and 90 days, respectively. Retrieved specimens were examined grossly, and calcium analysis and measurements of tissue collagen and water content were carried out. The results showed that, compared with glutaraldehyde fixed specimens, monosodium glutamate postfixation treated specimens had less calcification (calcium 104.93 + 50.94 versus 141.58 +/- 58.10 at 45 days and 103.07 +/- 76.48 versus 199.33 +/- 53.44 at 90 days, micrograms/mg dry weight, p < 0.01), higher collagen content (hydroxyproline 5.50 +/- 1.29 versus 3.58 +/- 1.48 at 45 days and 5.64 +/- 0.87 versus 4.25 +/- 0.65 at 90 days, micrograms/mg wet weight, p < 0.01), and higher water content (68.00 +/- 6.95% versus 61.33 +/- 8.83% at 90 days, p < 0.05) (mean +/- SD, paired t test). We conclude that monosodium glutamate couples with residual aldehyde, which significantly reduces calcification of glutaraldehyde fixed porcine aortic valves while preserving a higher tissue collagen and water content after implantation. The preserved tissue collagen and water content of the implants is closer to that of unimplanted native valves.