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Biomedical subjects

K E Andersen

Publications and source records attributed to K E Andersen.

At least 163 records · Page 9Linked to original sources
PubMed1985

Sensitivity and subsequent "down regulation" of sensitivity induced by chlorocresol in guinea pigs.

Chlorocresol was shown to have great potential for contact sensitization in the guinea-pig maximization test at the Day-21 challenge; 2 weeks later, the reactivity was significantly decreased. Cyclophosphamide (250 mg/kg) was interperitoneally injected and used as a modulator for the immune response. When cyclophosphamide was administered 3 days before the first challenge, the decrease in reactivity from Day 21 to Day 35 was reversed. This indicates that the reduction in sensitivity was caused by an immunologic mechanism--probably the formation of suppressor cells. This phenomenon is called the "down regulation" of sensitivity and may operate in eczema patients who have lost patch-test reactivity.

Animals↗
PubMed1985

Biocide patch tests.

Routine patch testing with a series of 6 industrial biocides containing methylene-bis-thiocyanate (Cytox 3522), benzisothiazolin-3-one (BIT), chlorocresol (Preventol CMK), 2-n-octyl-4-isothiazolin-3-one (Kathon 893), polyhydroxymethylene monobenzylether (Preventol D2) or 1,3,5-tris (hydroxy-ethyl) hexahydrotriazine (Grotan BK) was carried out in 6 Danish out-patient clinics to evaluate guinea pig allergy test results with the same compounds. A total of 1652 consecutive patients with dermatitis were tested. The usefulness of this patch test battery was limited. There were a few positive reactions to Cytox 3522, BIT and the 2 formaldehyde releasers, Preventol D2 and Grotan BK. These reactions could not, however, be explained. The MOAHL-index (% of Male patients, Occupational cases, Atopic patients, Hand eczemas, and Leg ulcers/stasis dermatitis) for patients from the 6 clinics showed equal frequencies of male patients and atopics, but significant differences in the frequencies of occupational cases, hand eczemas, and leg ulcers/stasis dermatitis, indicating possible variations in referral patterns, use of patch tests, and/or environmental factors.

Animals↗
PubMed1985

Contact sensitivity and bioavailability of chlorocresol.

Chlorocresol sensitization from 5 topical preparations was determined in guinea pigs using the cumulative contact enhancement test. Chlorocresol 5% in olive oil/acetone (4/1), and 5% in aqueous suspension stabilized with carbomer 941 were more sensitizing (55% and 60% of the animals positive, respectively) than chlorocresol 5% in propylene glycol with or without carbomer 941 (20% positive). The sensitization from a saturated aqueous chlorocresol solution (about 0.38% w/v) was comparable to that of a 5% propylene glycol solution containing 13 times more chlorocresol. The fraction of the applied dose (from each preparation) that remained in the bandage material and the patch test skin site was determined by combined gas chromatography-mass spectrometry using an isotopic dilution technique. From 0.2% to 1.6% of the applied doses remained at the patch test skin sites as free chlorocresol. 75% of the chlorocresol in aqueous suspension permeated the skin in contrast to 34% and 35% of the chlorocresol in olive oil/acetone (4/1) and propylene glycol, respectively. In spite of the same amount of chlorocresol absorption from the 2 latter preparations, they showed a significant difference in sensitizing capacity. No simple relationship between the sensitization rates and the calculated bioavailability was observed with the preparations tested.

Animals↗
PubMed1985

Induction of formaldehyde contact sensitivity: dose response relationship in the guinea pig maximization test.

The sensitizing potential of aqueous formaldehyde was evaluated with the guinea pig maximization test (GPMT) in two laboratories (Copenhagen and Stockholm) using different guinea pig strains. Six intradermal (0.01%-3%), and 6 topical (0.5%-20%) concentrations were used for induction, and formaldehyde 1% and 0.1% was used for challenge. The incidence of contact sensitivity depended on the intradermal, but not on the topical induction dose. Statistical analyses showed a non-monotonous (non-linear) dose response relationship. The estimated maximal sensitization rate in Copenhagen was 80% after intradermal induction with 0.65% formaldehyde; in Stockholm it was 84% after induction with 0.34%. The data from the two laboratories could be described by parallel displaced dose response curves suggesting that the guinea pig strain used in Stockholm was significantly more susceptible to formaldehyde than the strain used in Copenhagen. The EC50 (formaldehyde concentration at which 50% of the guinea pigs were sensitized) at the 72 h scoring and a 1% challenge concentration, was 0.061% in Copenhagen and 0.024% in Stockholm.

Administration, Topical↗
PubMed1985

Quantitation of contact allergy in guinea pigs by measuring changes in skin blood flow and skin fold thickness.

Skin blood flow determined by laser Doppler flowmetry (LDF) and skin fold thickness (SFT) have been used to quantitate allergic contact dermatitis in the guinea pig maximization test (GPMT) using chlorocresol as the allergen. The closed patch test procedure itself influenced both LDF and SFT measurements when determined in 12 sham-treated guinea pigs. The LDF was maximal at 24 hours and the SFT at 48 hours. Before correlating the quantitative measurements with the conventional visual scoring in test and control animals the value from a nearby control site was subtracted from the test site values. The correlations were highly significant (p less than 0.001-0.05) indicating that the quantitative methods were useful supplements to the visual scoring as a measure of interobserver and interlaboratory differences.

Animals↗
PubMed1985

Guinea pig maximization test: effect of type of Freund's complete adjuvant emulsion and of challenge site location.

Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline with 30% (v/v) ethanol or saline, respectively. Relative viscosity was used as one measure of physical properties of the emulsion. Higher degrees of sensitization (but not rates) were obtained at the 48 h challenge reading with the oil/propylene glycol and oil/saline + ethanol emulsions compared to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions.

Abdomen↗
PubMed1984

Yeast RNA polymerase III. Chromatographic, catalytic and DNA-binding properties are highly dependent on the type of anion.

The chromatographic, catalytic and DNA-binding properties of yeast RNA polymerase III are highly affected by both concentration and type of salt. The type of anion is an especially important modulating factor for the enzymological properties of the enzyme. When acetate or sulfate anions are substituted for chloride anions, RNA polymerase III exhibits a higher affinity for DEAE-Sephadex A25, becomes able to transcribe DNA at relatively high ionic strength and shows a significant increase in the binding strength to DNA. A quantitative analysis of the binding of the enzyme to single-stranded DNA shows that the number of ionic contacts in the complex is not affected by the type of anion, but the nonionic contribution to the binding constant is significantly increased when acetate is substituted for chloride.

Anions↗
PubMed1984

The sensitizing potential of metalworking fluid biocides (phenolic and thiazole compounds) in the guinea-pig maximization test in relation to patch-test reactivity in eczema patients.

The sensitizing potential of seven industrial antimicrobial agents was evaluated using the guinea-pig maximization test. Preventol O extra (o-phenylphenol) did not produce a sensitization reaction. Preventol ON extra (sodium salt of o-phenylphenol), Preventol GD (dichlorophene) and Proxel XL and HL containing 1,2-benzisothiazolin-3-one were weak sensitizers, while Preventol CMK and Preventol L, both containing chlorocresol, were classified as extreme potential sensitizers. Both the weak and the extreme experimental sensitizers are occasional human sensitizers. The interpretation of the test results is discussed.

Animals↗
PubMed1984

Multiple application delayed onset contact urticaria: possible relation to certain unusual formalin and textile reactions?

An unusual type of contact urticaria to formalin is described, based on 4 patients and experiments in 14 volunteers. The contact urticaria appeared on healthy skin only following repeated open applications or after a single application on slightly diseased skin. The possible relation of this phenomenon for patients claiming textile intolerance is discussed. Further tests are required to reveal the mechanism of this delayed onset contact urticaria to formalin.

Adolescent↗
PubMed1984

Guinea pig maximization tests with formaldehyde releasers. Results from two laboratories.

The guinea pig maximization test was used to evaluate the sensitizing potential of formaldehyde and 6 formaldehyde releasers (Forcide 78, Germall 115, Grotan BK, Grotan OX, KM 200 and Preventol D2). The tests were carried out in 2 laboratories (Copenhagen and Stockholm), and although we intended the procedures to be the same, discrepancies were observed, possibly due to the use of different animal strains, test concentrations and vehicles. The sensitizing potential was in general found to be stronger in Stockholm compared to Copenhagen: formaldehyde sensitized 50% of the guinea pigs in Copenhagen and 95% in Stockholm. For Grotan BK, the corresponding rates were 20% and 74%. Forcide 78, KM 200 and Preventol D2 sensitized 20% to 25% of the animals in Copenhagen, while Germall 115 and Grotan OX sensitized 60% to 70% of the animals in Stockholm.

Animals↗
PubMed1984

How sensitizing is chlorocresol? Allergy tests in guinea pigs versus the clinical experience.

Chlorocresol is a biocide with widespread use in industry and pharmaceutical products. It is an occasional human contact sensitizer. The sensitizing potential of chlorocresol was judged strong using the guinea pig maximization test (GPMT) and doubtful in the less sensitive open epicutaneous test (OET). When different induction concentrations were used, the results indicated an optimal sensitizing concentration above which no further increase in the sensitization rate occurred. Rechallenge 2 weeks later showed a marked decrease in sensitivity. Consecutive human patch tests with chlorocresol 2% in pet. showed 11 reactions among 1462 patients tested, but none were explainable and reproducible during re-tests and provocative use tests, indicating that the GPMT overestimated the sensitization potential. The results from guinea pig allergy tests cannot stand alone but have to be validated by other sources of information.

Animals↗
PubMed1984

The baboon syndrome: systemically-induced allergic contact dermatitis.

The catchword "baboon syndrome" is used to denote a characteristic distribution pattern of systemic allergic contact dermatitis. Diffuse erythema of the buttocks, upper inner surface of the thighs, and axillae are characteristic features. We describe 3 cases provoked by ampicillin, nickel and mercury. The condition may be overlooked and suspected of being a textile dermatitis or seborrhoeic dermatitis of the elderly.

Adult↗