Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Collodion”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1968

The rates of interchange of ions across fixed charge membranes in bi-ionic systems.

This paper examines the applicability of the Nernst-Planck approach in treating the relationship between the initial rates at which critical ions interexchange across permselective membranes in bi-ionic systems and the rates of self-exchange of these ions across the same membranes. Data are presented for five species of univalent cations with two types of cation permeable membranes, a polystyrene sulfonic acid-collodion matrix membrane, and an oxidized collodion membrane; five species of univalent anions were studied with a protamine-collodion matrix anion permeable membrane. Except with systems involving H(+) ion, the experimentally found relationships between the rates of interexchange and the rates of self-exchange were in agreement, in most cases within +/-5%, with the values calculated from an expression in which interaction between the critical ions in the membrane is not taken into account. In systems with H(+) ion, the experimental rates of interexchange were from 27% to 40% less than calculated values.

Acetates↗
PubMed1977

Attenuation of canine nephrotoxic glomerulonephritis with an extracorporeal immunoadsorbent.

A novel immunoadsorbent is described in which soluble canine glomerular basement membrane (GBM) antigen was immobilized in collodion membranes adherent to small charcoal particles. As much as 80% of the added GBM antigen was retained in the collodion-charcoal. The binding of GBM antibody to immobilized GBM antigen in vitro and in vivo was demonstrated. For in vivo studies, an extracorporeal circulation system was established, and mongrel dogs were then injected intravenously with GBM collodion-charcoal for 4 h. Renal tissue was examined by fluorescence and light microscopy for the deposition of heterologous gamma globulin and glomerular inflammation before and after the extracorporeal procedure. Results showed less deposition of heterologous IgG and less inflammation in experimental dog kidneys than in control kidneys. There was no evidence of release of 131I-labeled GBM from the immunoadsorbent at the conclusion of perfusion experiments and no significant biochemical or hematologic alterations. Finally, extracorporeal immunoadsorbent treatment was capable of attenuating the early heterologous phase of passive canine nephrotoxic nephritis and may have a potential role in the therapy of anti-GBM-mediated nephropathy.

Animals↗
PubMed2005

Simple compressive method for treatment of auricular haematoma using dental silicone material.

Most of the previous treatment methods for auricular haematoma are inconvenient for both patients and doctors because they are time-consuming and complex and must be performed under sterile conditions. The purpose of this study was to evaluate the effectiveness of a simple compressive method using a dental (silicone) impression material and comparing it with other methods for treatment of auricular haematomas. The authors aspirated a haematoma and then placed a mixed base and catalyst of silicone putty material on the anterior and posterior surfaces of the auricle in the shape of an inverted U for seven days. From the 24 cases managed with this method, 23 cases (95.8 per cent) were successfully healed. Eight patients were treated with a collodion-cotton wool cast and 16 of 19 patients were successfully treated with dental cotton-wool rolls. The average number of those visiting the hospital was 2.7 for the collodion-cotton wool cast, 6.9 for the dental cotton-wool roll, and 3.1 for dental silicone. The mean treatment durations were 8.1 days for the collodion-cotton wool cast, 13.8 days for the dental cotton-wool roll, and 8.6 days for dental silicone. The authors believe that this compressive method using dental silicone material is simple and appropriate for the treatment of auricular haematoma.

Adolescent↗
PubMedDate not supplied

Coated charcoal haemoperfusion.

We have made use of the principle of artificial cells to microencapsulate charcoal by coating an ultrathin membrane directly on to the surface of individual activated charcoal granules. This way the enclosing membrane prevents any free powder from going into the circulation. At the same time, blood platelets are prevented from being removed by the activated charcoal. Since 1970, we have been carrying out clinical trials in patients for acute drug poisoning, chronic renal failure, liver failure and other conditions. Our earlier results have stimulated a number of other polymer coated charcoal systems to be studied and produced in a number of other centres. At present there are at least ten coated charcoal haemoperfusion devices being used. They vary somewhat in membrane thickness, membrane permeability, blood compatibility and efficiency. It is therefore important not to make generalizations based on the results obtained for the less effective and less blood compatible systems. Collodion (cellulose nitrate) membrane coated charcoal is sufficiently blood compatible for use in uraemia and acute intoxication. In conditions with very sensitive platelets (e.g., hepatic failure) we showed earlier that by adsorbing albumin on to collodion, a highly blood compatible system can be obtained. This approach has been extended in three ways: instead of albumin, protein A can be incorporated into the collodion coating, resulting in an immunosorbent system for clinical trial in cancer therapy; albumin can be used to coat synthetic immunoadsorbent for blood group antibody to allow clinical application; albumin can also be used to coat resins to make them blood compatible.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗
PubMed1984

Generation of human C3a, C4a, and C5a anaphylatoxins by protein A of Staphylococcus aureus and immobilized protein A reagents used in serotherapy of cancer.

Protein A (SpA) alone or immobilized on bacteria (e.g., Cowan strain I), collodion charcoal, or on Sepharose have been used in serotherapy of cancer in humans and experimental animals. Because SpA forms complexes with IgG that can activate complement, and the physiologic response during treatment often involves hypocomplementemia and reactions that are similar to those induced by anaphylatoxins, we used sensitive and specific radioimmunoassays to test the ability of SpA reagents to generate C3a, C4a, and C5a from human serum. The yield of anaphylatoxins depended on the dose of SpA, with the maximum generation of C3a (47 to 55 micrograms/ml) and C5a (1.4 to 1.9 micrograms/ml) being produced with levels of SpA that were maximally precipitated from serum. Maximum C4a levels (up to 15 micrograms/ml) were obtained at concentrations of SpA equal to or greater than the dose required to give optimal precipitation. The maximum concentrations of anaphylatoxins correspond to essentially quantitative conversions of C3 to C3a, C4 to C4a, and 40% of C5 to C5a after correction for levels found in serum incubated in pyrogen-free saline. Preformed insoluble complexes prepared from either serum or monomeric IgG also were capable of generating anaphylatoxins in fresh whole serum up to levels approximately equal to those observed in serum treated directly with an optimal amount of SpA. The preformed complexes from serum or IgG generated similar high concentrations of anaphylatoxins when carried through four sequential incubations with fresh serum, and complexes that contained approximately 1 microgram SpA were still active. Preincubating the insoluble complexes with chicken anti-SpA serum did not alter their activity. Incubation of serum with collodion charcoal coated with SpA, in a system that models the perfusion technique used to treat cancer, produced complexes that generated significant levels of C3a compared with levels found in serum passaged over albumin charcoal or in untreated serum. The C3a levels in serum from the albumin collodion charcoal were not significantly different from those found in untreated serum. Similar amounts of C3a, C4a, or C5a were observed in serum incubated with differing numbers of bacteria representing a strain of S. aureus rich in cell bound SpA (Cowan strain I) or a strain (Wood 46) deficient in SpA. This suggests that in intact bacteria, cell wall factors other than SpA (e.g., peptidoglycan) are predominantly responsible for generating anaphylatoxins.(ABSTRACT TRUNCATED AT 400 WORDS)

Anaphylatoxins↗
PubMed1987

A polymeric controlled drug delivery device for peptides based on a surface desorption/diffusion mechanism.

Further investigations of the mechanisms underlying continuous peptide delivery from a newly developed Accurel polypropylene/collodion device are described. This module was prepared by lumen-loading an aqueous peptide solution into a piece of microporous Accurel polypropylene tubing which was subsequently end-sealed and encapsulated by a collodion membrane. By using vasopressin (VP) as a 'model' peptide, various aspects of the known semi-reversible protein/polymer surface interaction are shown to be present for VP and polypropylene i.e. prominent adsorption on the large surface area, which follows a bimodal adsorption isotherm, but with very limited desorption, and which can be enhanced by exchange with other proteins. Based on these findings as well as the observed steady state levels of VP on 24 h immersions in a small fixed volume, the previously proposed mechanism of pseudo-zero-order release could be evaluated further: the adsorbed peptide molecules function as a stock of near-constant activity, since desorption is rather limited, and as long as rapid exchange of bound peptide by external proteins can be prevented by a sufficiently thick (greater than 60 micron) collodion membrane, a slow long-term diffusion process will take place. Under 'infinite sink' conditions, the devices gave linear cumulative release curves for weeks. The present module is a novelty among the known membrane-controlled drug-delivery reservoir systems, since it has been loaded by an unsaturated drug solution and because the encapsulating membrane is not the sole release-rate-controlling factor.

Adsorption↗
PubMed1977

Thermoosmosis through charged membranes.

Thermoosmosis through oxidized collodion and collodion-sulfonated polystyrene interpolyrene interpolymer membranes has been observed in KCl solutions of various concentrations. The effective temperature difference acting for thermoosmosis was determined by measuring the thermal membrane potential appearing on both sides of membrane. It was found that the velocity of thermoosmosis is proportional to the effective temperature difference and the proprtionality constant (themoosmotic coefficient) is a function of electrolyte concentration. The dependence of the thermoosmotic coefficient of charged membranes on the electrolyte concentration is found to have a characteristic feature.

Collodion↗
PubMed2001

Application of the transition state theory to water transport across cell membranes.

We have applied the transition state theory of Eyring et al. (The Theory of Rate Processes, McGraw-Hill, 1941) to water transport across cell membranes. We have then evaluated free energy (Delta F(not equal)), enthalpy (Delta H(not equal)) and entropy (Delta S(not equal)) of activation for water permeation across membranes, such as Arbacia eggs, Xenopus oocytes with or without aquaporin water channels, mammalian erythrocytes, aquaporin proteoliposomes, liposomes and collodion membrane. Delta H(not equal) was found to be correlated with Delta S(not equal). This is so-called Delta H(not equal) and Delta S(not equal) compensation over the ranges of Delta H(not equal) and Delta S(not equal) from 2 to 22 kcal/mol and from -26 to 45 e.u., respectively, indicating that low Delta H(not equal) values correspond to negative Delta S(not equal). Large positive Delta S(not equal) and high Delta H(not equal) values might be accompanied by reversible breakage of secondary bonds in the membrane, presumably in membrane lipid bilayer. Largely negative Delta S(not equal) and low Delta H(not equal) values for aquaporin water channels, aquaporin proteoliposomes and porous collodion membrane could be explained by the immobilization of permeating water molecules in the membrane, i.e., the partial loss of rotational and/or translational freedoms of water molecules in water channels.

Animals↗
PubMed1975

Adsorption of DNA molecules to different support films.

Protein-free adsorption of the DNA of the Escherichia coli bacteriophage T7 to carbon, collodion, aluminium-beryllium and aluminium films was studied. It was found that the appearance of DNA strands depended greatly upon the kind of support film used. Direct adsorption of DNA to aluminium-beryllium or aluminium films yielded specimens with 'thin and long' and 'thick and short' regions along the strand. Well extended, uncoiled and unaggregated DNA molecules were obtained only when DNA was adsorbed to carbon, collodion or mica in the presence of intercalating dyes such as ethidium bromide. Adsorption properties of the different films are well correlated with their surface charge. Aluminium-beryllium films carry a strong positive surface charge, aluminium films a weak positive charge and carbon films a weak negative charge. It is suggested that for the preparation of specimens by spontaneous adsorption of well extended and unaggregated strands it is necessary that the DNA molecule is stiffened by a ligand such as an intercalating dye, and that the charge on the surface of the support film is opposite to the charge of the macromolecule.

Adsorption↗
PubMed1978

[In vitro evaluation of adsorbents used in haemoperfusion (author's transl)].

The properties of six adsorbents for Haemoperfusion were investigated in vitro: Amberlite XAD-2; Amberlite XAD-4; Haemocol; collodion coated charcoal; albumine-collodion encapsulated charcoal and activated carbon fibers. Carbromal and diazepam are most quickly removed from aqueous solutions by Amberlite XAD-2 and XAD-4. Of the charcoal containing materials, Haemocol eliminates most rapidly carbromal and diazepam; while activated carbon fibers remove phenobarbital faster. When heparinized blood is perfused, a remarkable reduction in platelet count is observed. The drop is most pronounced with Amberlite XAD-2 and XAD-4, but even when using charcoal preparations the platelet depletion can reach 10% of the original number over 5 hours. Haemolysis is most pronounced with Amberlite XAD-2, XAD-4 and Haemocol. As the efficiency of the adsorbents towards the various drugs differ and as their adverse effects also vary, the decision for a particular material will have to be made according to the individual case.

Adsorption↗
PubMed1975

Measurement of membrane potential and estimation of effective fixed-charge density in membranes.

Electrical potentials Em arising across cross-linked phenolsulfonate membrane separating NaCl solutions of molality M1 and M2 have been measured at 25 degrees C. These values of Em have been used in the Nernst equation to calculate values for the apparent transport number ti(app) for the counterion or the co-ion in the membrane. Values of ti(app) together with the limiting value for the cation transport number in the aqueous phase have been used in the equation developed by Kobatake and co-workers to evaluate the membrane permselectivity Ps as a function of external electrolyte concentration. With the help of the equation relating Ps to phiX, the effective fixed-charge density in the membrane (where phi is a constant, 0 less than phi less than 1, and X is the membrane stochiometric charge density and can be evaluated by chemical analysis of the membrane phase), values for phiX and phi have been determined. Values of phi were low in dilute solutions and increased with increase in the concentration of the external solution. Similar behavior was noted in the case of another membrane system, cross-linked polymethacrylic acid in contact with KOH solutions. On the other hand, the membrane system, "untreated" collodion in contact with KCl solutions, exhibited a behavior in which the values of phi, low in dilute solutions, increased and then decreased following a gradual increase in the external concentration. This slight divergence in its behavior was attributed to the heterogeneity of the collodion membrane structure. The reliability of this potentiometric method to estimate effective fixed-charge density in membranes has been discussed in relation to a similar but old method due to Teorell, Meyer and Sievers. Also the significance of the values derived for phi has been pointed out.

Evaluation Studies as Topic↗
PubMed1989

Characterization of an infection structure-specific gene from the rust fungus Uromyces appendiculatus.

Uredospores of the plant pathogen, Uromyces appendiculatus, infect leaves of the bean plant, Phaseolus vulgaris, through stomata. Physical stimuli provided by the stomate induce differentiation of the germ tube to form a series of infection structures involved in host colonization. Contact between the uredospores and the oil-collodion membranes induces formation of infection structures in the absence of the host. This report describes the characterization of a Uromyces gene, INF24, that is induced by the physical stimulus of an oil-collodion membrane. INF24 contains a 450-bp open reading frame which encodes a 16.4-kDa polypeptide. The N terminus of the INF24-encoded protein, and the C terminus of human single-stranded DNA-binding protein are both glycine-rich and share homology.

Amino Acid Sequence↗
PubMed1999

Distribution of salicylic acid in human stratum corneum following topical application in vivo: a comparison of six different formulations.

Distribution of salicylic acid in human stratum corneum from treatment of six different formulations was assessed by quantitation of drug content in sequentially tape-stripped stratum corneum after a single 2-h dose was applied unoccluded to skin on the ventral forearm of four female subjects. The profile and total amounts of stratum corneum removed in 20 tape-strips varied among different types of formulations. With or without normalization by the total stratum corneum weights removed, the extent of drug delivery to the stratum corneum decreased in the following order: SA (5%) > > SAC (10%), Duofilm (16.7%) > TSSS (2%) > SAO (10%), Salic (2.5%), the percentage in parentheses indicating the salicylic acid concentration in each formulation. The greatest topical bioavailability was observed for the alcoholic solution containing glycerol (SA). The 10% collodion formulation (SAC) was found to deliver an amount of salicylic acid into the stratum corneum 2-fold greater than 10% ointment formulation (SAO). Use of absorption ointment (TSSS) also increased the uptake of salicylic acid into the stratum corneum in comparison with formulations based on simple ointment (SAO) and oil in water (o/w) cream (Salic). The partitioning of salicylic acid from collodion formulations (SAC and Duofilm) appeared to be concentration-independent. The results of this study indicate that topical bioavailability of salicylic acid in the stratum corneum varies substantially among different formulations.

Adhesives↗
PubMed1986

Ingestion of Compound W, an unusual caustic.

A case of an unusual caustic ingestion involving Compound W, an over the counter wart remover is presented. Chemical burns of the tongue, pharynx and larynx developed. The active ingredient in this preparation: salicylic acid in a flexible collodion vehicle produces caustic injury through a keratolytic action, which may be enhanced by the presence of collodion.

Administration, Oral↗
PubMed2003

[The early history of the artificial kidney].

Only very few remember Georg Haas as the scientist who--in 1924--was the first to successfully conduct an extracorporal hemodialysis on a patient in Giessen. Haas began his experiments in 1914 shortly after joining the Medical Clinic of the University of Giessen. Neither protocols nor any of the set-ups were preserved from these early experiments. In addition, the WW1 interrupted Haas' early experiments between 1917-1919. Until 1923 Haas himself never mentioned his early experiments. "Outside circumstances" and a "shortage of materials" (hirudin) prevented Haas from continuing his work on hemodialysis. Also, the early trials had disappointing results as the experimental animals, mostly dogs, died after a few hours. The hirudin preparations Haas had used turned out to be toxic. While the toxicity of the hirudin preparations prevented the application of dialysis in humans early on, the war with its many cases of nephritis provided new inspiration to develop dialyzing techniques. Haas experimented with reed tubes, calf peritoneum and paper membranes. None of these worked satisfactorily. Not until Pregl introduced collodion tubes was the first barrier overcome. Haas started experimenting with collodion tubes produced by himself. However, the toxicity problem with the hirudin preparations remained. Haas resumed the hemodialysis experiments in 1923. Significantly, 1923 was the year when Necheles published his work describing an alleged purified leech extract. Necheles' paper also described American experiments that focused on dialysis in animal trials. It was J. Abel of Baltimore who informed Haas that purified hirudin was available. After learning of this availability through the American studies in 1924, Haas conducted his first hemodialysis on a uremic patient in late 1924. This experiment lasted only 15 minutes and was without complications. A second dialysis attempt followed in 1925 and even lasted 30 minutes. Finally, four further experiments followed in 1926. The turning point was the availability of purified heparin from 1925 on. Haas, who in 1924 conducted the first dialysis using hirudin, in 1927 conducted the first hemodialysis using heparin. Further hemodialysis treatments followed. Haas concluded: "The problem of hemodialysis is still in the first steps of practical application. Nevertheless it could be shown that hemodialysis has developed sufficiently to find applicability even in patients with serious kidney ailments and irritable heart...Hemodialysis was not only well tolerated but also brought a temporary subjective improvement. Of course, the technical aspects of hemodialysis still need improvement and further development to qualify as detoxicant therapy." A look at the early history of the artificial kidney and its applicability to humans reveals that J. Abel conducted the first hemodialysis on experimental animals. It also becomes evident that Haas conducted the first hemodialysis in humans. The American experiments pursued the quantitative optimization of the method in animal trials, while Haas' experiments focused on the development of a therapeutic method following the principle "primum nil nocere."

Anticoagulants↗
PubMed1984

Proteinase-treated photoreceptor discs. Photoelectric activity of the partially-digested rhodopsin and membrane orientation.

Photoreceptor discs from rod outer segments of cattle retina were treated with (a) papain, (b) thermolysin or (c) trypsin, the procedures resulting in the cleavage of the rhodopsin polypeptide chain between (a) 323 and 324, 236 and 237, 241 and 242, (b) 327 and 328, 240 and 241, or (c) 339 and 340 amino acid residues, respectively. In all the cases, partially digested rhodopsins proved to be competent in generating photoelectric potential and increasing membrane conductance of the discs adsorbed onto phospholipid-impregnated collodion film. The kinetics of generation and dissipation of photopotential as well as of formation of metarhodopsin II and of the light-induced rhodopsin protonation were found to be the same in the partially digested preparations and in the intact one. Incubation of papain-treated or thermolysin-treated discs at pH 6.0 induced formation of inside-out vesicles which, when incorporated into the collodion film, generated an oppositely directed photopotential. Treatment of such vesicles with papain gave rise to further cleavages of the polypeptide localized between 30 and 31, 186 and 187 amino acid residues. One more proteinase-sensitive site, localized between 104 and 105 residues, has been discovered in the inside-out vesicles treated with thermolysin. This fact consistent with the scheme of the 'seven column' arrangement of the visual rhodopsin [Ovchinnikov, Yu. A. (1982) FEBS Lett. 148, 179-191]. Rhodopsin, when treated with papain on both sides, was deprived of sixty amino acid residues being split in two sites in the middle part of the polypeptide, but was still active as a photoelectric energy transducer. The main specific feature inherent in the photoelectric response of the papain-treated or thermolysin-treated rhodopsin and absent from the native protein is that the former survives addition of long trains of saturating flashes when the response of the intact preparation becomes negligible. This effect was shown to be due to conversion of partially digested rhodopsin to a photolytic product that at room temperature lived for minutes even in the presence of NH2OH. A 532-nm laser flash effectively converted this product back to rhodopsin.

Animals↗
PubMedDate not supplied

Holocarboxylase synthetase deficiency presenting as ichthyosis.

Holocarboxylase synthetase deficiency is a rare autosomal recessive disorder of biotin metabolism. Clinical manifestations usually present within the first few days of life and include severe acidosis, feeding difficulties, breathing abnormalities, vomiting, seizures, progressive loss of consciousness, coma, and death. Skin findings, when present, usually develop within the first weeks of life and are described as an erythroderma-like dermatitis involving the eyebrows, eyelashes, and scalp. We were asked to consult on a newborn with a collodion membrane and severe metabolic acidosis who was eventually diagnosed with holocarboxylase synthetase deficiency and ichthyosis. The diagnosis of holocarboxylase synthetase deficiency might be considered in a newborn with collodion membrane, ichthyosis, and acidosis.

Diagnosis, Differential↗
PubMed1981

Contact allergy to dithranol.

During treatment with a dithranol-containing collodion for common warts, a patient developed a eczematous reaction on the treated sites and the extremities. Patch testing revealed a contact allergy to dithranol. Two applications of the collodion cured the warts within 3 weeks. It is argued that contact allergy to dithranol occurs more frequently than is suspected.

Adult↗