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Biomedical subjects

P Lisi

Publications and source records attributed to P Lisi.

At least 19 recordsLinked to original sources
PubMed2005

Reactivity to euro coins and sensitization thresholds in nickel-sensitive subjects.

BACKGROUND: The 1- and the 2-euro coins consist of nickel alloys, which release nickel. The nickel released by far exceeds the amount allowed by the European Union Nickel Directive referring to products intended to come into direct and prolonged contact with the skin. As there is only temporary contact with the skin, the clinical relevance of nickel-containing coins with regard to nickel dermatitis is a matter of debate, although there is evidence that the nickel released from the coins affects some nickel-sensitive subjects through occupational exposure. OBJECTIVES: Our aim was to study skin reactivity to euro coins, and to correlate the frequency and intensity of coin patch test responses to sensitization thresholds to nickel. PATIENTS AND METHODS: Sixty-four nickel-sensitized and 30 non-nickel-sensitized subjects were patch tested with serial dilutions of nickel sulfate (5, 1, 0.5, 0.1, 0.05, 0.01 and 0.005% in distilled water) and with coins. Italian coins (500, 200, 100 and 50 lira) and euro coins (2 and 1 euros, 20 and 5 euro cents) were used for patch testing and compared. RESULTS: The application of 1- and 2-euro coins to the skin induced eczematous reactions, being more frequent and intense in comparison with those provoked by other coins. A correlation between intensity of responses to coin patch tests and sensitization threshold to nickel was observed. Patients with the strongest reactions to 1- and 2-euro coins showed positive responses to the lowest nickel concentrations. CONCLUSIONS: The nickel content in euro coins represents a possible health hazard, especially for highly nickel-sensitive subjects. We recommend that nickel sulfate patch tests should be performed at different concentrations to determine sensitization thresholds at least in individuals with occupational exposure to coins.

Adult↗
PubMed1999

T-lymphocyte cytokine profiles in compositae airborne dermatitis.

Compositae airborne dermatitis is a well-recognized disorder characterized by erythematosquamous lesions and papules on light-exposed areas. The presence of positive patch test reactions and the absence of specific serum IgE suggest delayed-type hypersensitivity, the murine model of which is characterized by a Th1 cytokine production profile [high amounts of interferon (IFN)-gamma and interleukin (IL)-2; little or no IL-4 and IL-5]. The aim of this study was to evaluate the cytokine profile of T-cell lines and T-cell clones from peripheral blood in a 38-year-old non-atopic male woodcutter affected by seasonal airborne contact dermatitis. The patient showed positive patch test reactions to several Compositae extracts (Achillea millefolium, Chamomilla recutita, Tanacetum parthenium, T. vulgare) and sesquiterpene lactone mix. On prick testing with Compositae and other plants, serum-specific IgE levels and phototesting were negative or normal. Allergen-specific T-cell lines produced with Compositae extracts showed a good in vitro cell proliferation only to C. recutita extract. Serial cloning performed using the C. recutita-specific T-cell lines revealed an alphabeta+CD4+ phenotype with high amounts of IFN-gamma and IL-4 in T-cell clones. Thus, these cells expressed a preferential Th0 phenotype. These data suggest that in addition to IFN-gamma, other T-cell derived cytokines, such as IL-4, may play a part in the immunopathogenesis of contact dermatitis.

Adult↗
PubMed1998

Is benzoquinone the prohapten in cross-sensitivity among aminobenzene compounds?

Cross-sensitivity in allergic contact dermatitis is a simultaneous allergy to 2 or more contact substances which have in common an antigenic determinant or a metabolic derivative. One of the most notable examples is the cross-sensitivity among aromatic compounds which may be oxidized in vivo to benzoquinone (BQ). However, it has also been hypothesized that the allergenicity and cross-sensitization are modulated by the chemical reactivity of the substituents in the para position. A serial dilution of BQ (from 1% to 0.1% in pet.) and three 1,4-substituted benzene derivatives (p-aminophenol, hydroquinone, metol), theoretically capable of conversion to BQ by oxidation, were patch tested in 22 p-phenylenediamine (PPD) positive patients and in 20 controls. The patients and a further 116 subjects with a positive history of sensitivity to 1 or more aminoaromatic compounds were also tested with some haptens of the para group (PPD, p-aminobenzoic acid, p-aminodiphenylamine, benzocaine, procaine chloride, p-toluenediamine sulfate). The results show that (i) the optimal patch test concentration for BQ was 0.2%, (ii) only 4 of the 22 patients allergic to PPD gave a clearly positive allergic reaction to BQ, and (iii) the number of positive reactions to the aromatic compounds was correlated with the presence of activating (-NH2, -OH, -CH3) and deactivating (-COOH) groups in the para position or, perhaps, with their effect on percutaneous penetration. The data suggest that BQ is not the only intermediate in the cross-sensitization of para group haptens. This is probably conditioned by other oxidation products and/or the chemical structure of the substituents in position 4 of the benzene ring.

Adult↗
PubMed1997

Skin tests in the diagnosis of eruptions caused by betalactams.

The aetiologic evaluation of adverse cutaneous reactions to penicillins is still not an easy problem to solve. Skin testing is usually carried out intradermally with benzylpenicilloyl polylysine (BPO-PPL) and minor determinant mixture (MDM), but these are often unsuitable for the detection of sensitivity to betalactam antibiotics. 101 selected subjects, with different cutaneous reactions to betalactams and with a clinical history of positive challenge, were skin tested (patch test, prick test, intradermal test) with a standard betalactam series (amoxycillin, sodium penicillin G, ampicillin, bacampicillin, aztreonam, ceftriazone, BPO-PPL, MDM). 1 or more positive reactions to skin tests, mainly to intradermal tests, were observed in 47.5% of the subjects studied, especially in those with maculopapular eruptions, urticaria/angioedema and drug reactions caused by ampicillin and amoxycillin. Cross-sensitivity was demonstrated in 22.8% of cases and was due almost solely to the semisynthetic penicillins. Finally, to increase the yield in detecting positive patients, it is necessary that ampicillin and amoxycillin be tested in addition to major and minor determinants.

Adolescent↗
PubMed1996

Statistical evaluation of the persistence of acquired hypersensitivity by standardized patch tests.

Numerous studies have focused attention on the influence of various biological and environmental factors on contact hypersensitivity. In order to evaluate the persistence and/or modification of allergic contact sensitivity to a number of common contact sensitizers, the same standardized patch tests were repeated on 174 subjects with contact sensitivity after a time lapse of 5 years (1987-1992). In 18.4% of the cases, 1 or more sensitivities were lost; 28.7% of the patients had a higher number of positive patch tests after 5 years, while the remaining 52.9% of the patients showed no change in the number of positive patch tests. In 88%, the positive allergens were unchanged, whereas in the remaining 12% of the subjects, they showed 1 or more variations. The association between the allergens most often positive was calculated for both the 1st and the 2nd patch test results. Moreover, to evaluate the frequency of an allergen's positivity, we studied the disappearance of old sensitivities and the appearance of new sensitivities by the McNemar test. Cobalt chloride was the only allergen with a significant frequency of new positivities over the period of observation (p < 0.01). Logistic regression analysis was performed to evaluate the possible influence of positive tests to other allergens, and of some clinical findings associated with contact dermatitis, on the sensitivity to cobalt chloride in 1987 and in 1992.

Adult↗
PubMed1995

The OKT3 Antibody Response Study: a multicentre study of human anti-mouse antibody (HAMA) production following OKT3 use in solid organ transplantation.

Human anti-murine antibody titres following patient exposure to the monoclonal antibody Orthoclone OKT3 (muromonab-CD3) are determined by laboratories using diverse analytical methods which are not standardized and whose concordance is not established. A multicentre study group therefore compared testing for IgG anti-OKT3 antibody among seven laboratories. A set of 270 sera was obtained from 30 heart, 30 kidney and 30 liver transplant recipients with no previous exposure to OKT3 who were receiving OKT3 for induction immunosuppression. Sera were collected from each patient prior to and at 24 +/- 2 days and 31 +/- 2 days following initial OKT3 exposure. Identical aliquots of all 270 sera were tested for IgG anti-OKT3 antibody by each laboratory. In addition, the limit of detection of each laboratory's method was estimated by titration of an affinity-purified IgG anti-OKT3 reference material of known concentration. Anti-OKT3 antibody formation differed greatly among the three organ groups. Cardiac patients demonstrated the least sensitization and almost exclusively lower titres, while kidney recipients had more frequent and higher titre antibody formation. Liver recipients yielded the highest sensitization rate and the most frequent high titre sera. Importantly, the seven laboratories differed widely in the number of pretreatment sera reported as positive (ranging from 0% to 41% among laboratories), the number of post-OKT3 sera reported as positive (17-63%), the number of post-OKT3 samples with titre > or = 1000 (2-31%), and the number of patients sensitized 19-69%). Concordance among laboratories was highly variable, with interlaboratory agreement ranging from 38% to 83% on the sample titres assigned to 180 post-OKT3 sera. Many of the discordant results were consistent with differences in the limit of detection of the analytical methods, which ranged from 0.19 microgram/ml to > or = 15 micrograms/ml, a nearly 100-fold difference among laboratories. This study demonstrated the presence of both good concordance and significant discordance among laboratories in determining human anti-mouse antibody titres, and demonstrated that common titre categories (100, 1000, 10,000) were not equivalent among laboratories. The level of concordance among methods should be considered when comparing anti-OKT3 antibody results from different centres and their correlation with clinical events. Universal comparative testing, patterned after proficiency testing programmes, is needed to assess differences among laboratories and to bring uniformity and a sound interpretative basis to this field of testing.

Adult↗
PubMed1995

Occupational hand dermatitis in hospital environments.

Health care personnel form the 5th category at major occupational risk of skin disease in Italy. The aim of this study was to assess the prevalence and clinical relevance of contact dermatitis in a group of 1301 employees of the Perugia Monteluce Hospital (658 females and 643 males; mean age 39.8 years) who answered a self-administered questionnaire elaborated by the authors. The subjects with anamnestic hand dermatitis and/or atopic mucosal reactions were clinically examined and submitted to skin tests (patch and/or prick tests). Contact dermatitis of the hands and/or forearms occurred in 21.2% and was significantly more frequent (p < 0.001) in women, subjects under 31 years of age, workers in internistic and surgical fields, cleaners and nurses. In the majority of cases (94.9%), the lesions were irritant in origin and mainly related to disinfectants (especially, chlorhexidine gluconate and glutaraldehyde) and gloves (latex proteins and starch glove powder, rather than accelerators and additives of rubber). Finally, atopy seemed to favour the onset of hand dermatitis. The importance of these results for preventive measures of contact dermatitis in hospital employees is discussed.

Adult↗