Search PubMed⌕ Search

Biomedical subjects

W Aberer

Publications and source records attributed to W Aberer.

At least 73 records · Page 4Linked to original sources
PubMed1998

Genotype and phenotype of N-acetyltransferase 2 (NAT2) polymorphism in patients with contact allergy.

We investigated whether patients with contact allergy differed from non-contact-allergic, non-atopic controls with regard to genotype and phenotype of the polymorphic enzyme N-acetyltransferase 2 (NAT2). 55 contact-allergic patients recruited from the Information Network of Departments of Dermatology (IVDK) were compared to 85 controls from among local health care personnel. NAT2 activity was calculated from HPLC analysis of the ratio of the caffeine metabolites 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and 1-methylxanthine (1MX) in the urine. NAT2 genotype was determined by polymerase chain reaction (PCR). A statistically significantly increased proportion of rapid acetylators was found in contact-allergic patients. This may have 2 possible implications: acetylation may enhance contact sensitization; or NAT2 status may be a genetic marker for contact sensitizability.

Acetylation↗
PubMed1997

Epidemiological significance of bufexamac as a frequent and relevant contact sensitizer.

Bufexamac-containing ointments and creams are widely used by many patients with eczematous disorders as an alternative to topical corticosteroids. Recent studies provide evidence of a notable prevalence of contact sensitization in patch test populations. The aim of this study was to assess the frequency of use of this topically-applied drug by eczema patients in general, and to evaluate its potential to cause allergic contact reactions. 500 routinely patch tested patients (f:m = 377:123) were tested with bufexamac 5% and Parfenac ointment (the only commercial product available in Austria) in addition to the standard and other series of the German Contact Dermatitis Group. The packaging of the commercial product was shown to the entire study population, to decide whether or not they had ever used this product. In addition, their general practitioner was contacted to verify the anamnestic data. A total of 30 patients agreed that they had definitely used bufexamac, 5 others having probably applied it. The indication for and the duration of treatment were noted. Positive and relevant patch test reactions to bufexamac, as well as the bufexamac-containing ointment, were seen in 20 out of these 35 patients (57%), and sensitization occurred even after short-term application. Our study demonstrates that bufexamac has to be assumed to be a topical drug with a very high sensitization rate in an unselected patch test population (4% of 500 patients), and should therefore be added to the standard series.

Administration, Topical↗
PubMed1997

Olive oil--contact sensitizer or irritant?

Adverse cutaneous reactions to topically applied olive oil are seldom reported, and positive patch tests to it are mostly regarded as allergic. To evaluate such "positive" patch test reactions, 77 female (mean age: 44 years) and 23 male eczema patients (mean age: 46 years) were prospectively patch tested with freshly prepared olive oil. Tests were performed openly (including ROAT) as well as using Al-tests and Finn Chambers on Scanpor. 5 patients (2 male) showed "positive" test reactions (all patients at the Al-test site, 3 at the Finn Chamber site, 1 with ROAT). In only 1 patient could the reaction be classified as probably allergic, in contrast to previous reports. In conclusion, olive oil is very weakly irritant in general, but bears relevant irritant capacity when applied under occlusive conditions. Therefore, olive oil appears to be less than suitable for the topical therapy of patients with venous insufficiency and associated eczema of the lower extremities.

Adult↗
PubMed1997

National rates and regional differences in sensitization to allergens of the standard series. Population-adjusted frequencies of sensitization (PAFS) in 40,000 patients from a multicenter study (IVDK).

Sensitization rates to contact allergens vary between centers and are influenced by sex and age. Eliminating the latter 2 factors by standardization of data by age and sex, the present analysis addresses possible differences between centers remaining after elimination of these confounders, and analyzes other factors which might influence rates, e.g., the MOAHL index. Overall standardized rates were well within the range reported in previous studies and may be regarded as representing the rates of the "patch test population" in Central Europe (e.g., nickel sulfate 12.9%, fragrance mix 10.5%, balsam of Peru 7.3%, thimerosal 5.6%). For this analysis, data of those departments which contributed more than 2000 patients, or of those with extreme proportions concerning sex, age and occupational cases were selected. Patients from these 10 departments differed considerably with regard to the items of the MOAHL index and with regard to standardized rates. The items of the MOAHL index proved to be suitable for describing different patch test populations and for explaining some differences between centers. Only 'atopic dermatitis' seems to have little influence on (standardized) rates. Face dermatitis is not yet represented in the MOAHL index, but should be included, together with age > 40 years, in an extended index (acronym: MOAHLFA). Regional allergen exposure (with striking differences between East Germany, West Germany and, to a lesser extent, Austria) seems to have a great influence on the sensitization pattern observed in a department. In addition, sociological factors may influence sensitization rates, which is exemplified by high rates of nickel allergy in a socially defined subgroup. Future studies should focus on these factors, as well as on factors concerning patch test practices and quality control.

Adult↗
PubMed1996

[Correlation between chronic urticaria and depression/somatization disorder].

In a multicenter study, 100 patients with chronic urticaria were examined with a standardized personality test (Giessen test), a standardized symptom questionnaire (Giessener Beschwerdebogen) and a specially developed questionnaire concerning symptoms, history and behaviour during symptomatic periods. Almost one third of the patients showed elevated scores both for depression and for symptoms that are often associated with depression. It therefore seems worth-while examining such persons more specifically and possibly treating them by psychosomatic methods. The present results do not allow the classification of chronic urticaria as a somatization disorder. Since one-third of the patients had symptoms of depression, combined dermatological and psychosomatic approach may make it possible to offer them an appropriately targeted treatment.

Adolescent↗
PubMed1996

[Food allergies and intolerance--epidemiologic studies].

The lack of standardized definitions and reliable test methods disclosed a wide field of often incorrect speculation on the incidence and importance of allergies and intolerance reactions to food and its ingredients. It was only recently that, based on guidelines in statements from national and international scientific societies, serious studies were initiated to determine the correct incidence and prevalence of these problems. First results clearly document that lay people and the press overestimate the role of food as causative agent for disease, which might result in unjustified dietary restrictions and exaggerate the problem, whereas the scientific community might have underestimated the dimensions. New developments in the field of antigen characterization and new guidelines for a correct test performance should soon enable unproven alternative methods which frequently hurt the person concerned more than they help, to be disposed of.

Adolescent↗
PubMed1996

[Amalgam allergy--diagnosis and consequences].

Allergy to dental amalgam is rare--in contrast to Press reports and public opinion. Whereas sensitivity to one or more mercury salts is quite frequently detected in the patch test, it is seldom of clinical relevance. In this report we define the limited indications for performing an allergy test, describe the exact test criteria and delineate the consequences of a positive test result. A critical appraisal of the result is essential in order to avoid unnecessary procedures which are expensive and far from being effective, may even be potentially dangerous.

Dental Amalgam↗
PubMed1995

Natural and recombinant enzymatically active or inactive bee venom phospholipase A2 has the same potency to release histamine from basophils in patients with Hymenoptera allergy.

BACKGROUND: A complementary DNA encoding the major bee venom allergen phospholipase A2 (PLA) has been characterized recently. Recombinant PLA was produced in Escherichia coli and purified to apparent homogeneity. Natural PLA was compared with recombinant PLA in its ability to release histamine from blood basophils. METHODS: A synthetic gene encoding the mature form of PLA was expressed in E. coli, and the polypeptide was purified to homogeneity by affinity chromatography and refolded, yielding fully enzymatically active PLA. In addition, we have produced a genetically engineered enzymatically inactive variant by substitution of a single amino acid residue in the catalytic center. A standard histamine release assay was used to compare the potency of natural PLA with correctly folded enzymatically active and inactive recombinant PLA to release histamine from blood basophils of nine patients with bee venom allergy. RESULTS: Recombinant enzymatically active PLA and purified natural protein were equally effective in releasing histamine from sensitized basophils. By comparing the histamine-releasing capacity of enzymatically active and inactive recombinant allergen, we further demonstrate that catalytic activity is not a requirement for allergenicity in the effector phase. Denaturation of natural PLA or incorrect folding of recombinant protein resulted in a total loss of allergenic potency. CONCLUSION: We demonstrate the feasibility of producing native-like recombinant allergens with or without enzymatic activity. We also provide evidence for the requirement of correct three-dimensional structure of PLA to induce histamine release from basophils and thus evidence for its recognition by IgE.

Bee Venoms↗