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Showing papers on "Glutaraldehyde published in 1994"


Journal ArticleDOI
TL;DR: The structure and reactivity of glutaraldehyde protein immobilization is detailed, which shows a complex chemistry that is transparent to most practitioners of immobilization.
Abstract: Immobilization of proteins to solid matrices has been performed for the last thirty years and has provided numerous examples of successful preparations with use in enzyme reactors, sensor preparation and immunodiagnostics. Among the arsenal of coupling reagents and procedures, glutaraldehyde plays a critical role due to its reliability and ease of use. It displays a complex chemistry that is transparent to most practitioners of immobilization. In this article we detail the structure and reactivity of glutaraldehyde protein immobilization.

262 citations


Journal ArticleDOI
TL;DR: The polyelectrolyte complex of polysaccharide was employed to achieve the controlled release and effective targeting of 5FU by the CNSs.
Abstract: Small-sized chitosan-gel nanospheres, CNSs (average diameter 250 nm), containing 5-fluorouracil (5FU) or immobilizing 5FU derivatives (aminopentyl-carbamoyl-5FU or aminopentyl-ester-methylene-5FU) were prepared by the glutaraldehyde crosslinking technique and the emulsion method. When chitosan was crosslinked with glutaraldehyde, these 5FU derivatives were simultaneously immobilized to CNSs by means of Schiff's base formation. The CNSs were coated with anionic polysaccharides, such as 6-O-carboxymethyl-N-acetyl-α-l,4-polygalactosamine/Na (CM-NAPGA/Na), 6-O-carboxymethyl-chitin/Na (CM-chitin/Na), and sodium hyaluronate, through formation of a polyelectrolyte complex membrane to give CNS/polyanion, i.e., CNS/G, CNS/C, and CNS/H, respectively. The polyelectrolyte complex of polysaccharide was employed to achieve the controlled release and effective targeting of 5FU by the CNSs. The release rate of 5FU from the CNSs could be controlled by immobilization of 5FU, degree of deacetylation of chitosan use...

156 citations


Journal ArticleDOI
TL;DR: In this article, the aqueous swelling kinetics of a series of crosslinked chitosan (cr-CS) with glutaraldehyde (GA) interpenetrating polyether hydrogels have been studied as functions of pH, the N-deacetylation degree, the amount of crosslinking agent, the electrolyte composition in solution, temperature, and gel composition.
Abstract: The aqueous swelling kinetics of a series of crosslinked chitosan (cr-CS) with glutaraldehyde (GA) interpenetrating polyether hydrogels have been studied as functions of pH, the N-deacetylation degree of chitosan, the amount of crosslinking agent, the electrolyte composition in solution, temperature, and gel composition. Based on these results, the swelling mechanism of the hydrogels was discussed. The release profiles of chlorhexidini acetas from the semi-IPN were also investigated. © 1994 John Wiley & Sons, Inc.

145 citations


Journal ArticleDOI
TL;DR: In this article, the structure of chitosan membranes chemically modified with aldehydes, such as glutaraldehyde and n -butyl aldehyde, was analyzed by evapomeation.

143 citations


Journal ArticleDOI
TL;DR: DPPA-treated pericardium had a resistance to collagenase digestion similar to that of glutaraldehyde- or hydrazine- treated pericARDium, corroborated by resistance to bacterial collagen enzyme digestion.
Abstract: Cross-linking of collagen-based biomaterials increases their strength and persistence in vivo. Recently, we described an efficient cross-linking process via the formation of acyl azide groups on methylated carboxyl groups of collagen using hydrazine and nitrous acid (referred to here as the hydrazine method). In this report, we propose a simpler, faster way to prepare acyl azide groups and to cross-link collagen-based biomaterials, using diphenylphosphorylazide (DPPA) as a reagent. After determining the optimal conditions of cross-linking with DPPA, we compared the efficiency of this protocol with that using hydrazine and with the classical glutaraldehyde treatment. In order to validate and quantitate the extent of reaction, the degree of crosslinking was determined by the measure of the free primary amino group content of the samples. Treatment of native bovine pericardium with 0.5% DPPA for 24 h led to efficient cross-linking, corresponding to a 50% decrease in the free primary amino group content of the sample and raising its thermal stability from 62.8 up to 81.3°C. In comparison, the thermal stabilities of glutaraldehydeor hydrazine-treated pericardium were 85 ± 0.4°C and 83.4 ± 0.1°C. Similar decreases in free primary amino group content and increases in thermal stability were obtained for collagen films treated with DPPA, glutaraldehyde, or hydrazine. These results were corroborated by resistance to bacterial collagenase digestion: DPPA-treated pericardium had a resistance to collagenase digestion similar to that of glutaraldehyde- or hydrazine-treated pericardium. Residual DPPA content: the concentration of phosphorus in tissue treated with 0.5% DPPA was not significantly different from that of untreated tissue. Treatment by DPPA thus appears to be an efficient, rapid method for cross-linking collagenbased biomaterials. © 1994 John Wiley & Sons, Inc.

112 citations


Patent
04 Mar 1994
TL;DR: A macromolecular microparticle composition formed by dehydrating an aqueous macromulecule solution and crosslinking the dehydrated macromellecules with a cross-linking agent while in a liquid phase or with heat is described in this paper.
Abstract: A macromolecular microparticle composition formed by dehydrating an aqueous macromolecule solution and crosslinking the dehydrated macromolecules with a crosslinking agent while in a liquid phase or with heat. Preferably, the dehydrating agent is a polymer mixture of polyvinylpyrrolidone and polyethylene glycol, the crosslinking reagent is glutaraldehyde, and the macromolecule is a protein, most preferably an immunoglobulin. Methods of use for research, diagnostics and therapeutics are also provided.

111 citations


Journal ArticleDOI
TL;DR: Glutaraldehyde (pentanedial) is a dialdehyde that displays potent bactericidal, fungicidal, mycobactericidal, sporicidal, and virucidal activity.
Abstract: Glutaraldehyde (pentanedial) is a dialdehyde that displays potent bactericidal, fungicidal, mycobactericidal, sporicidal, and virucidal activity Pertinent to its activity is its interaction with amino groups in proteins and enzymes, but this simplistic statement masks the manner in which it inactivates various types of microorganisms Notwithstanding its toxicity for medical staff, glutaraldehyde remains an invaluable compound for high-level disinfection purposes in endoscopy units

94 citations


Journal ArticleDOI
TL;DR: In this paper, the β-galactosidase immobilization on chitosan beads of 2.2 mm diameter was performed at 37 o C with a 1% glutaraldehyde concentration and the addition of galactose.
Abstract: The β-galactosidase immobilization on chitosan was studied. Enzymatic activity and stability were determined for the different conditions used. The best results were obtained on chitosan beads of 2.2 mm diameter where the immobilization process was carried out at 37 o C with a 1% glutaraldehyde concentration and the addition of galactose. The higher activity values of the immobilized enzyme compared with those of the free β-galactosidase could be obtained over a larger pH range and were at higher pH's and temperatures, but the best activity is only 10.7% of the free enzyme values

89 citations


Journal ArticleDOI
TL;DR: In this article, a polyvinyl alcohol/cyclodextrin (PVA/CD) membrane was used in the pervaporation of ethanol/water mixtures, which increased the water selectivity of the water/ethanol, especially at lower (

82 citations


Journal ArticleDOI
TL;DR: The data in this study suggest that a monofunctional fixative can pre-react with the amino acids of collagen to effectively block further fixation of collagen with a second fixative, and may be associated with collagen branching.
Abstract: Collagen from a native tissue is fixed with a polyepoxy compound (PC) for use as a new biologic prosthetic material. Prior studies have shown that this biomaterial has comparable properties with collagen fixed with glutaraldehyde (GA), and thus has great promise for biomedical applications. A prior kinetic study indicated that the reaction between the functional groups of collagen and the multifunctional epoxy EX-313 is a 2.5th-order reaction. The purpose of this study was to understand the mechanism of the amino acid-PC reactions in a fixation process. Bovine arteries were fixed with a monofunctional PC (EX-131) and a multifunctional PC (EX-313) as a function of fixation time. A sequential fixation with a second fixative was used to identify the available remaining reactive sites from a prior fixation. The denaturation temperature (Td) was measured on each sample. Because the denaturation temperature is a direct indication of crosslinking of individual amino acids with the fixative, the increase in Td of a subsequent fixation may be indicative of the available remaining amino acids. The fixation index was measured on each sample to reflect the increase of fixation completion in a sequential fixation process. The fixation index and crosslink data also revealed that the reactive amino acids for EX-131 and EX-313 may not be exactly the same. The data in this study suggest that a monofunctional fixative can pre-react with the amino acids of collagen to effectively block further fixation of collagen with a second fixative. This amino acid masking may be associated with collagen branching. Collagen branching and its effect on denaturation temperature are described.

79 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the influence of degree of crosslinking on the hydrophilicity and mechanical strength of polyvinyl alcohol (PVA) membrane, and the kinetics of cross-linking of PVA membrane with glutaraldehyde was examined.
Abstract: Prior to investigate the influences of degree of crosslinking on the hydrophilicity and mechanical strength of polyvinyl alcohol (PVA) membrane, the kinetics of crosslinking of PVA membrane with glutaraldehyde was examined. The reaction variables were temperature, hydroxyl group concentration of PVA membrane, and concentrations of glutaraldehyde and sulfuric acid in crosslinking solution. The overall reaction rate of crosslinking was suggested, which agrees well with the experimental results. The crosslinking reaction is approximately first order with respect to the concentration of hydroxyl group of PVA membrane, of glutaraldehyde, and of sulfuric acid. The activiation energy was estimated to be about 5.77 kcal/mol. It was also found that the degree of crosslinking of PVA membrane can be easily changed by controlling the reaction variables.

Journal ArticleDOI
TL;DR: The europium signal in time‐resolved fluorescence microscopy was shown to be free of autofluorescence when strong cross‐linking fixation with glutaraldehyde was used and the signal‐to‐background ratio obtained was 2,400 or better.
Abstract: In the present study europium chelates were introduced as alternative fluorescent labels for microscopy and their effect on enhanced autofluorescence caused by the glutaraldehyde fixative was investigated. Glutaraldehyde fixation was used to stabilize the cells for a permanent mount after the immunocytochemical reaction. The europium signal in time-resolved fluorescence microscopy was shown to be free of autofluorescence when strong cross-linking fixation with glutaraldehyde was used and the signal-to-background ratio obtained was 2,400 or better. It was also shown that the europium signal was stable in daylight and at room temperature. Fluorescent europium chelate used in this experiment provides excellent contrast and long-term stability for the samples with glutaraldehyde fixation and permanent mounting. © 1994 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: In this article, the features of the reaction between sitka spruce wood and non-formaldehyde reagents, i.e., glyoxal, glutaraldehyde, and dimethylol dihydroxy ethyleneurea (DMDHEU), were investigated from the aspects of moisture adsorption and bending creep properties.
Abstract: The features of the reaction between sitka spruce wood and non-formaldehyde reagents, i. e. glyoxal, glutaraldehyde, and dimethylol dihydroxy ethyleneurea (DMDHEU), were investigated from the aspects of moisture adsorption and bending creep properties. To the moisture adsorption data, Hailwood-Horrobin adsorption equation was applied, and whole adsorbed water was separated into hydrated water and dissolved water which correspond to monolayer and multilayer adsorption, respectively. In the treatments with non-formaldehyde reagents, the decrease of equilibrium moisture content was mainly attributed to the decrease of dissolved water, but not largely to that of hydrated water. This suggested that the reagent in the multilayer adsorption region contributed pronouncedly to suppress the moisture adsorption by the bulking and cross-linking effects, but that the reagent in the monolayer adsorption region did not considerably. The creep deformation and remaining strain of the specimens treated with glyoxal and glutaraldehyde were as small as those of formaldehyde treatment. Also by the DMDHEU treatment, creep deformation was restrained to some extent. The eminent creep restraint effect by these treatments showed the formation of cross-linkings, although the crosslinkings were not stable to the drastic water leaching.

Journal ArticleDOI
TL;DR: To obtain a better relative activity, a method was developed and further modified to increase the surface area of the support system by using polyacrylamide and relative activity enhancement of 68% was achieved in the gelatin–glutaraldehyde system.
Abstract: β-Galactosidase (EC 3.2.1.23) was immobilised onto a gelatin carrier system by crosslinking. Glutaraldehyde and chromium(III) acetate were used as crosslinking agents. The effect of pH on enzyme activity, kinetic parameters and reusability of the immobilised enzyme were investigated. To obtain a better relative activity, a method was developed and further modified to increase the surface area of the support system by using polyacrylamide. Relative activity enhancement of 68% was achieved in the gelatin–glutaraldehyde system.

Journal ArticleDOI
TL;DR: The Dextranox-MPEG crosslinked Nanospheres showed a significantly reduced plasma protein adsorption on the particle surface compared with glutaraldehyde crosslinked nanospheres.
Abstract: Human serum albumin (HSA) nanospheres with a size less than 200 nm in diameter were prepared using a modified coacervation method and crosslinking with methyl polyethylene glycol modified oxidized Dextram (Dextranox-MPEG) which created a sterically stabilizing polyethylene oxide surface layer surrounding the nanospheres. The crosslinking efficiency and the surface characteristics of glutaraldehyde and Dextranox-MPEG crosslinked HSA nanospheres were determined and compared. The zeta potential of the Dextranox-MPEG crosslinked particles was significantly lower than that of glutaraldehyde stabilized particles. The existence of a hydrated steric barrier surrounding the nanospheres was confirmed by an electrolyte and pH induced flocculation test. The Dextranox-MPEG crosslinked nanospheres showed a significantly reduced plasma protein adsorption on the particle surface compared with glutaraldehyde crosslinked nanospheres.

Journal ArticleDOI
TL;DR: In this paper, the effect of temperature, concentration and fixation time on the shrinkage temperature of collageneous tissues was investigated and a measure of the degree of crosslinking was determined.
Abstract: Glutaraldehyde (GA) crosslinking (fixation) of collageneous tissues is a widely used method for the preparation of implantible tissues to be used as biomaterials. In an attempt to optimize the fixation process, experiments were carried out with two types of collagen (native collagen membrane and synthetic collagen sheet) to study the effect on crosslinking of temperature, GA concentration and fixation time. Secondly, stimulation of GA diffusion was studied and finally, a procedure of low T-presoaking followed by brief exposure to high temperatures was investigated. As a measure of the degree of crosslinking the shrinkage temperature (T s) was determined. Temperature (20°C or 45°C), concentration (0.1% or 1.0%) or fixation time (4 or 24 h) were found to be positively correlated with the T s of the collagen sheets. Whereas untanned collagen exhibits a T s of around 60°C, short-term (1 or 5 min), high-temperature (50°C) fixation with a 0.1% GA solution caused the shrinkage temperature to increase to 72°C and 85.1°C, respectively. Fixation with 0.01% GA for 5 min at 50°C appeared equally effective as 1 min with 0.1% GA (T s=70°C). Microwave irradiation showed to be slightly more effective in enhancing the crosslinking process compared with conventional heating. Surprisingly, at any combination of temperature, concentration and fixation periods of 4 h or 24 h, an increased T s towards the central regions of the collagen was observed. Soaking the samples at 20°C (1 h) or at 0°C (3 h) with subsequent short-time heating to 45°C caused an almost equal rise in T s throughout the collagen samples and is therefore recommended for preparing implantable tissues.

Journal ArticleDOI
TL;DR: The rate of fatty acid production in the TSLP-EMR was linear with time showing no enzyme deactivation in an operating time of 80 h, and the kinetics observed in the two reactors was different: an equilibrium reaction product-inhibited for the E-emR and an apparent irreversible reaction of zero order for the T SLP- EMR.
Abstract: Two enzyme membrane reactors (EMR), (1) with one substrate (olive oil) in an oil-in-water emulsion (E-EMR) and (2) with two separated liquid phases (oil and water) (TSLP-EMR), have been studied for the conversion of the triglycerides to fatty acids and glycerol. The enzyme was Candida cylindracea lipase confined on the pressurized face or entrapped in the sponge side of capillary ultrafiltration membranes. Two methods for immobilizing the enzyme in the TSLP-EMR were used: ultrafiltration on a virgin membrane and ultrafiltration on glutaraldehyde pretreated membranes. A multiple use of the reactor was obtained immobilizing the enzyme on the membrane preactivated with glutaraldehyde. The TSLP-EMR showed a specific activity of 0.529 mmol/(mg[center dot]h) versus a specific activity of 0.170 mmol/(mg[center dot]h) of the E-EMR. The rate of fatty acid production in the TSLP-EMR was linear with time showing no enzyme deactivation in an operating time of 80 h. The kinetics observed in the two reactors was different: an equilibrium reaction product-inhibited for the E-EMR and an apparent irreversible reaction of zero order for the TSLP-EMR. Taking into account that in the TSLP-EMR, compared to the E-EMR, (1) the specific activity was higher, (2) the specific rate was constant with the time, andmore » (3) the two products were already separated after the reaction, the TSLP-EMR configuration seems the more convenient.« less

Journal ArticleDOI
TL;DR: In this article, a novel hydrogel based on crosslinked chitosan with glutaraldehyde interpenetrating polyether polymer network was described, which can hydrolyse in acid at 37°C due to the cleavage of imine bonds within the network.
Abstract: This paper describes a novel hydrogel based on crosslinked chitosan with glutaraldehyde interpenetrating polyether polymer network. The gel can hydrolyse in acid at 37°C due to the cleavage of imine bonds within the network. At pH≥7, there is no hydrolysis. The pH-dependent release of cimetidine from the gel was also investigated.

Journal ArticleDOI
TL;DR: No histopathological evidence of glutaraldehyde induced responses was observed in the trachea, central airways, or lungs, while the larynx showed minimal changes, and there were clear increases in ULLI in association with acute and subacute cytotoxic responses, with similar concentration-response relationships.

Journal ArticleDOI
TL;DR: β-Galactosidase from Saccharomyces fragilis was covalently linked by glutaraldehyde to chemically modified corn grits, an inexpensive material with good mechanical properties for use in bioreactors and showed that the reaction rate was not limited by diffusion.

Journal ArticleDOI
TL;DR: In this article, a surface modified polyvinyl alcohol (PVA) gel membrane was used for protein transport and separation in a stirred diffusion cell through unmodified and surface modified PVA gels, and the surface modification was useful in increasing membrane selectivity while still maintaining good permeability.

Journal ArticleDOI
TL;DR: Yeast disguised in castor oil was protected from bead reinforcement by glutaraldehyde treatment, significantly strengthening bead stability while operating under acidic conditions and was demonstrated by continuous ethanol production by chitosan entrapped yeast.
Abstract: A new simple method for the preparation of chemically crosslinked chitosan beads is presented. It consists of the dropwise addition of 2–3% (w/v) low molecular weight chitosan solution containing 2% (w/v) glyoxal in 1% (w/v) tetrasodiumdiphosphate, pH 8.0. Immobilized viable baker's yeast (Saccharomyces cerevisiae) could be obtained via gel entrapment within the new beads when means preventing their direct contact with soluble chitosan were provided, “disguising” the cells until gelation and crosslinking were completed. Such means included cell suspension in castor oil or mixing with carboxymethyl-cellulose powder. Application of these means was shown to be necessary, as cells exposed to soluble chitosan immediately lost their viability and glycolytic activity. Yeast disguised in castor oil was also protected from bead reinforcement by glutaraldehyde treatment, significantly strengthening bead stability while operating under acidic conditions. This capability was demonstrated by continuous ethanol production by chitosan entrapped yeast. © 1994 John Wiley & Sons, Inc.

Journal ArticleDOI
TL;DR: In this paper, the separation of water/ethanol vapor mixtures through chitosan membranes and crosslinked chitosa membranes was studied by means of the vapor permeation technique.
Abstract: The separation of water/ethanol vapor mixtures through chitosan membranes and crosslinked chitosan membranes was studied by means of the vapor permeation technique. The permeation performance was discussed in terms of separation factor and permeation flux. Crosslinking the chitosan membrane by glutaraldehyde enhanced the selectivity. The highest separation factor obtained was 6000 for a crosslinked chitosan membrane with a degree of deacetylation of 100%.

Journal ArticleDOI
TL;DR: Cleaning was effective against heavy viral contamination while glutaraldehyde rapidly inactivated poliovirus even when dried to a surface in serum, to study the elimination of enteroviruses from endoscopes.

Journal ArticleDOI
TL;DR: In this paper, α-amylase and papain were immobilized onto the ultrafine silica particles with high efficiency by covalent cross-linking with glutaraldehyde, and both enzymes showed high activities.

Journal ArticleDOI
TL;DR: The parameters involved in immobilization of alkaline protease on nylon using glutaraldehyde as coupling agent and the characteristics of the immobilized enzyme were investigated and immobilized enzyme showed better thermal stability than the free enzyme.
Abstract: The parameters involved in immobilization of alkaline protease on nylon using glutaraldehyde as coupling agent and the characteristics of the immobilized enzyme were investigated. Optimum temperature and pH of both free and immobilized enzyme for the degradation of protein was found. Immobilized enzyme showed better thermal stability than the free enzyme. The reusability and storage stability of the immobilized enzyme was also studied.

Journal ArticleDOI
TL;DR: In this paper, the synthesis of a new crosslinked polymer by reaction of α,β-polyasparthydrazide and glutaraldehyde was reported, and different crosslinking degrees were obtained by varying the ratio between the aldehyde and the polymer.
Abstract: The synthesis of a new crosslinked polymer by reaction of α,β-polyasparthydrazide and glutaraldehyde is reported. Different crosslinking degrees were obtained by varying the ratio between the aldehyde and the polymer. The crosslinked polymer was characterized by water swelling tests and thermal analysis. In particular, the crosslinking density and its effects on the T g of the material were studied.

Journal ArticleDOI
TL;DR: It appears that modified chitosan surfaces may be an excellent sorbent system for haemoperfusion due to their high binding affinity for immunoproteins and blood compatibility.
Abstract: The use of adsorbents for the treatment of patients suffering from various immune diseases is still in its infancy. Therefore, the development of selective absorbents for the removal or decrease of immunoproteins from plasma is of great importance. In this study, chitosan, a natural polysaccharide having structural characteristics similar to glycosamino glycans, which is non-toxic and biocompatible, has been used for protein adsorption studies. Amino acids like phenyl alanine and tryptophan in different ratios are bonded to these polymers to observe immunoadsorption. Several layers of phenyl alanine or tryptophan have been coated covalently on chitosan beads using N2-plasma, carbodiimide or glutaraldehyde treatments. Scanning electron micrographs have revealed the surface morphological changes after such modifications. The surface modified chitosan beads have exhibited high binding affinity for gamma-globulin compared to bare beads. It is also observed that the amount of fibrinogen adsorption is reduced on modified substrate. A selective removal of IgG and IgM has also been observed with these modified matrix when tested with human plasma, using immuno diffusion methods. The modified chitosan membranes have demonstrated a reduction in platelet attachment, showing that these substrates have become more blood compatible. Hence, it appears that modified chitosan surfaces may be an excellent sorbent system for haemoperfusion due to their high binding affinity for immunoproteins and blood compatibility. Further studies are needed to determine the behaviour under clinical conditions.

Patent
16 May 1994
TL;DR: In this article, the authors provide a composition and method of administering same for inhibiting the growth of aerobic microorganisms, which includes the step of adding the oxidant and glutaraldehyde to industrial process waters.
Abstract: The present invention provides a composition and method of administering same for inhibiting the growth of aerobic microorganisms. The composition of the present invention includes sufficient amounts of an oxidant and glutaraldehyde. The method of the present invention includes the step of adding the oxidant and glutaraldehyde to industrial process waters.

Journal ArticleDOI
TL;DR: The incorporation of bovine serum albumin in the liposomal membrane to prevent leakage of the entrapped contents was studied in this paper, where it was found that the particle size increased after the treatment of glutaraldehyde.
Abstract: The incorporation of the bovine serum albumin in the liposomal membrane to prevent leakage of the entrapped contents was studied. Adsorption of bovine serum albumin was found on the liposomes. After the adsorption of bovine serum albumin, by the addition of glutaraldehyde, the serum albumin molecules cross-linked to themselves and stiffened the membrane structure of the liposomes. It was found that the particle size of the liposomes increased after the treatment of glutaraldehyde. However, there was no significant change in particle size for the liposomes with the stirring effect. Adriamycin, methotrexate, carboxyfluorescein and mitoxantrone were entrapped into this liposome system. The loading efficiency demonstrated a similar value for the liposomes with and without the treatment of glutaraldehyde. However, for the entrapment of adriamycin, there showed an increase in loading efficiency with the effect of glutaraldehyde. For the leakage examination, a decrease of the release rate of the adriamyc...