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Biomedical subjects

P Lisi

Publications and source records attributed to P Lisi.

At least 19 recordsLinked to original sources
PubMed1992

A multicentre study of contact sensitization in children. Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali (GIRDCA).

The results of 7 months of patch testing with a standard series of 26 allergens in 323 children with eczematous conditions or itching palmoplantar psoriasis under the age of 14 years are reported. 114 (35.3%) of the children had 1 or more positive reactions to this standard series. 28 children (8.7%) were polysensitive. On the basis of personal history, additional series of allergens and/or specific allergens were also tested. 61.7% (90/146) of positive reactions were considered relevant to the current dermatitis. Metals, medicaments, preservatives or fragrances, and shoe components were the major sources of contact sensitization. It is suggested that patch testing be done more frequently in evaluating dermatitis in children.

Adolescent↗
PubMed1992

Contact dermatitis in hairdressers: the Italian experience. Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali.

A multicenter study was performed in 9 Italian centers by members of the GIRDCA, to evaluate the frequency and source of contact sensitization in a group of 302 hairdressers with dermatitis. Occupational habits and use of preventive measures were specifically investigated both in these 302 hairdressers and in a further group of 240 hairdressers who answered a questionnaire. The results showed the presence of an occupationally relevant sensitization in 60.9% of the 302 hairdressers. This proportion included 52 hairdressers who had negative patch tests to the hairdressers' series but showed positive reactions to other allergens, such as nickel, rubber additives, preservatives and fragrances, which were judged relevant to their occupation. Among hair dyes, PPD caused 73 reactions (24.2%), PAP 32 reactions (10.6%), ONPPD 24 reactions (7.9%), and PTD 40 reactions (13.2%). A low incidence of sensitization was detected in our hairdressers to resorcinol and pyrogallol (1.3% for each substance). Among permanent wave allergens, positive reactions to GMTG were found in 11.3% of patients, while ATG gave a lower rate of positive reactions (5.0%). Allergic contact dermatitis due to APS was also relatively common (11.3%). 4 hairdressers in this study gave a positive reaction 30 min after a provocative test with latex gloves, patch testing to the rubber series being negative. Enquiry regarding preventive measures revealed that the majority of hairdressers use gloves when doing hair dyeing, but rarely use them for washing dyed hair or for doing permanent waving. The infrequent use of preventive measures by Italian hairdressers was confirmed by the results of the questionnaire, and possibly explains the high frequency of skin problems (12.5%) in the hairdressing population that was specifically interviewed.

Adolescent↗
PubMed1991

Minimum eliciting patch test concentration of thimerosal.

Positive patch test reactions to thimerosal 0.1% pet. (40/690 subjects: 5.8%) were more common in younger age groups, in the allergic contact dermatitis group and in subjects who had used contact lens solutions. In the 40 thimerosal-positive patients, the minimum eliciting quantity of preservative was evaluated using different test concentrations: 0.05% and 0.01% pet. (patch testing) and 1:10,000 in saline (intradermal testing). Cross-reactions between thimerosal and other mercury compounds and sensitivity to thiosalicylic acid were also examined. The results of the investigation demonstrate that many of the reactions to 0.1% thimerosal are probably irritant, because only half the subjects studied had positive patch tests when allergen concentrations 5 to 10x lower than that conventionally used for patch testing, were utilized. In these subjects, the average strength of patch test reactions was higher, intradermal testing was more often positive and cross-reactions between mercurials more frequent. These data indicate that the optimal eliciting patch test concentration for studying thimerosal sensitivity is 0.05% pet.

Adolescent↗
PubMed1989

Insulin resistance in porphyria cutanea tarda.

It has been reported that patients with porphyria cutanea tarda (PCT) develop carbohydrate (CHO) intolerance and manifest diabetes melitus (DM) more frequently than the normal population. In order to verify whether this is due to insulin resistance we studied 5 patients with PCT and 5 normal subjects matched for age, sex and weight. In all the patients an evaluation consisted of the glycemic curve and insulin response to an iv glucose tolerance test (IVGTT: 0.33 g/kg) as well as of an evaluation of the circulating monocyte insulin receptors. Blood samples were drawn in the basal state to measure plasma levels of NEFA, glycerol, and intermediate metabolites. The patients with PCT showed normal glucose tolerance which was obtained, however, at the expense of the elevated insulin levels: therefore a condition of insulin resistance was demonstrated in these subjects. An involvement of the lipid metabolism, observed by the raised levels of plasma NEFA and glycerol, was also evident. The insulin binding to circulating monocytes was reduced but not enough to justify the degree of insulin resistance observed. Therefore, it could be hypothesized, in agreement with similar studies, that a postreceptor defect is responsible for the insulin-resistance observed in patients with PCT and that the reduction of insulin receptors is determined by the down regulation in response to elevated insulinemic levels. An alteration of the porphyrin metabolism might be responsible for this disorder.

Adult↗
PubMed1987

Irritation and sensitization potential of pesticides.

A pesticide series of 36 substances was patch tested in 652 subjects to establish the optimal test concentration, and the frequency of irritant and allergic reactions. Allergic reactions to fungicides were found in 46: thiophthalimides (captan, folpet and difolatan) were the most common. Irritant and allergic reactions to other pesticides (insecticides, herbicides, etc.) were rare. Sensitivity to pesticides was significant in patients who work, or have worked on the land. Cross sensitivity to bisdithiocarbamates or thiophthalimides is possible.

Adolescent↗
PubMed1986

A test series for pesticide dermatitis.

A pesticide patch test series was tested in 200 subjects, 50 of whom were agricultural workers. Positive reactions to fungicides were found in 24, almost all to thiophthalimides, especially captan, difolatan and folpet. Reactions to bis-dithiocarbamates and benomyl were rare, and to other pesticides not significant.

Adolescent↗
PubMed1986

A highly sensitive immunoenzymometric assay involving "common-capture" particles and membrane filtration.

This highly sensitive immunoenzymometric method involves monoclonal antibodies, a common-capture microsphere, and a rapid, membrane-filtration separation step. The common-capture solid phase is monoclonal anti-fluorescein antibody convalently attached to 6.5 micron-diameter latex particles. In sandwich-type assays for large-molecule analytes, the capture antibody is conjugated with fluorescein isothiocyanate and the probe antibody is conjugated with beta-galactosidase (EC 3.2.1.23). In competitive assays for small analytes, the analyte-beta-galactosidase conjugate competes with the analyte in the clinical samples for the fluoresceinated capture antibody. After simultaneous incubation of the reagents for 2 h, the bound and unbound reagents are separated by filtration through the bottom of each well of a 96-well plate. Substrate (4-methylumbelliferyl-beta-D-galactopyranoside) is then added to the wells, and the rate of product formation is determined kinetically for 12 min. The rate is proportional to the concentration of analyte in the sandwich assays and inversely proportional in the competitive assays. The assay results for choriogonadotropin, thyrotropin, digoxin, and thyroxin show the assay to be sensitive, rapid, and applicable to any size analyte. With this system, several different sandwich and (or) competitive-type assays can be performed simultaneously on the same plate.

Antibodies, Monoclonal↗
PubMed1985

Contact sensitivity in children and adults with atopic dermatitis--a chronological study.

61 atopic dermatitis patients were subjected to a second patch testing 3-15 years (average 7.3 years) after the first contact sensitivity examination. The comparison between the results of the two studies revealed that 26.2% of patients had been sensitive to one or more haptens at the first patch testing and that 24.6% reacted positively at the second. 9 subjects (14.8%) still manifest contact sensitivity, while 6 (9.8%) reversed to positivity and 7 (11.5%) to negativity. The chemicals most frequently involved were nickel sulphate, potassium dichromate, benzoyl peroxide, diphenylguanidine. This study demonstrates that contact reactions are not linked to susceptibility to skin irritants in atopic dermatitis patients and that they tend to increase with time.

Adolescent↗
PubMed1979

Cellular and humoral immunity in psoriatic patients.

The degree of cellular immunity was found to be reduced in about 23% of 56 psoriatics, especially so in those with flexural and arthropathic lesions. Humoral immunity was only slightly reduced. Lysozyme activity levels in serum were normal, while those of healthy skin were depressed in 6 patients.

Adolescent↗
PubMed1975

Statistical association between psoriasis and diabetes: further results.

In a group of 200 psoriatic patients from the area of Umbria, Italy, diabetes mellitus occurred in a statistically highly significant association with psoriasis. Similar observations were made earlier in a series of 600 patients. The above correlation also occurred significantly more frequently in patients under 50 years and in male patients. Previous and present experience also demonstrate that psoriasis is statistically correlated with heredity for diabetes and obesity. The possible biological basis of psoriasis/diabetes association are tentatively outlined.

Adolescent↗