Allergenic degradation products of para-tertiary butylphenolformaldehyde plastic.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to E Seutter.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The quick passage of methyl methacrylate at 21 degrees C and 35 degrees C through seven surgeon's glove materials in a diffusion chamber was quantified by gas-chromatographic analysis. Polystyrene-butadiene dissolved in methyl methacrylate, latex and polychlorobutadiene showed reversible expansion, during which material from the samples dissolved. In order to prevent these phenomena from interfering with the analyses, experiments were performed with 4.7 M methyl methacrylate in ethanol. Even then, the time in which methyl methacrylate permeated the membrane was too short for sufficient protection. When using these gloves, the orthopaedic surgeon who is fixing endoprostheses is no doubt occlusively exposed to methyl and other methacrylates, benzoyl peroxide, rubber additives, etc. Of glove materials which are not surgically used, vinyl was inferior to latex, whereas a very thin polyethylene copolymer did not change in methyl methacrylate, showed better resistance to diffusion, but was insufficiently elastic and easily perforated. A better protective material is urgently needed.
Concomitant sensitization to hydroquinone and p-methoxyphenol occurred in sensitization experiments with acrylic monomers in guinea pigs. No relation between the concentration of the inhibitor in the monomers and the incidence of these concomitant sensitizations could be detected. Concomitant sensitization did not influence the cross reaction pattern of the acrylic monomers. The sensitizing potential of acrylic monomers is not influenced by the inhibitors, but some acrylic monomers seem to interfere with the sensitizing potential of the inhibitors.
Whole-body autoradiography was performed in the guinea pig with methyl (2,3-14C)-acrylate. Radioactive material quickly disappeared from the body after oral and, somewhat slower, after i.p. administration for the greater part. After administration in a closed cup on the skin a slow penetration in the dermis occurred preceded by the toxic effect, mainly a strong edema. In the first 16 h metabolism was primarily restricted to the skin, internal organs showed a slow rise in radioactivity. A large part of the labeled material was retained in the dermis. The detoxification was screened by estimating the urinary thioether content and respiratory carbon dioxide. This showed that in addition to oxidation to carbon dioxide the binding to SH-groups was the principal way of metabolism.
1. After administration to rats of methyl acrylate (I), methyl methacrylate (II) and methyl crotonate (III), urinary mercapturic acids were isolated and identified as the dicarboxylic acids N-acetyl-S-(2-carboxyethyl)cysteine (IV, R = H), N-acetyl-S-(2-carboxypropyl)cysteine (V, R = H) and N-acetyl-S-(1-methyl-2-carboxyethyl)cysteine (VI, R = H) and for a minor part as their monomethyl esters IV (R = CH3) and VI (R = CH3). 2. After a single dose of the acrylates (I), (II) and (III) (0.14 mmol/kg), the excretion of the thioethers amounted to 6.6 +/- 0.6, 0.0, and 2.0 +/- 0.6% dose respectively. 3. After 18 h previous administration of the carboxylesterase inhibitor tri-o-tolyl phosphate (0.34 mmol/kg) the excretion of the thioethers amounted to 40.6 +/- 2.1, 11.0 +/- 3.3, and 16.0 +/- 2.0% dose. 4. For methyl acrylate (I) the ratio of the excreted dicarboxylic acid and monomethyl ester was 20:1. After previous administration of tri-o-tolyl phosphate this ratio was 1:2.
Explore the source record for details and available documents.
Two patients showed occupational contact sensitization to a component present in the Nyloprint photopolymer printing plate. The component could not be identified chemically. It contains an acrylamide group. Both patients gave group-specific reactions to NN' methylene bis acrylamide. This must be a closely realted substance. Possible preventive measures are discussed. The manufacturer should have disclosed the allergic substance and instructed his customer adequately. A "philosophy" concerning this point is being developed.
In the metabolism of a systemically administered corticosteroid, one of three possible main pathways is determined by the position in the molecule of the substituents which are added in the drugs to the naturally occurring ones. (I) Chiefly, hydrogenation in ring A and/or the 20-position: cortisol, cortisoine, prednisolone, prednisone, and 6alpha-methylprednisolone (II) In the presence of a substituent in the 16-position mainly 6beta-hydroxylation: dexamethasone, betamethasone, and triamcinolone. (III) In the presence of a substituent in the 16-position, and fluorine in the 6alpha-position principally defluorination in the 6alpha-position and 6beta-hydroxylation: fluocortolone and paramethasone. Complete metabolism, in long-term use, can be expected in the case of the substances mentioned under II and III, but not of those under I. Enzyme induction, both actively and passively, is negligible in group I and marked in groups II and III.
Glutathione was estimated in 98 blood samples from dermatological patients; in only two cases, both of contact eczema, a value considerably below normal was found. Glutathione reductase was assayed in blood samples from 139 different patients and 21 normal controls. The activity was significantly higher in atopic dermatitis (17 patients). A significantly greater variable was found among patients with non methotrexate-treated psoriasis (44), light sensitivity (12) and scleroderma (5). In the methotrexate-treated psoriatic group (24) and mean and variability did not differ significantly from normal. In most hospitalized patients a low glutathione reductase activity rose within a few weeks, but in a case of dermatitis herpetiformis a very low level persisted for 3 months. Blood samples with very low glutathione reductase activity, taken from a case of psoriasis and from a patient on griseofulvin treatment, gave a positive peroxide test and tended to hemolyze; these returned to normal together with the glutathione reductase activity.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.