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Biomedical subjects

A Tosti

Publications and source records attributed to A Tosti.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1996

Contact dermatitis from fatty alcohols.

The aim of this study was to investigate the frequency of sensitization to fatty alcohols in a group of patients with suspected cosmetic or medicament contact dermatitis. From May 1992 to September 1995, we patch tested a series of 5 fatty alcohols on 146 patients. These included 108 females and 38 males aged from 13 to 72 years (mean age 42.5). These patients, who had previously been tested with the GIRDCA standard series, were selected because their clinical lesions or histories indicated topical preparations as the possible source of their contact dermatitis. High-grade fatty alcohols (> 99% pure) were used for testing. 34 patients (23.2%), 25 female and 9 male aged from 14 to 72 years, showed a positive patch test to fatty alcohols, 33 of them to oleyl alcohol. A total of 39 reactions were detected with 5 patients showing more than 1 positive reaction. Our results show that sensitization to oleyl alcohol is not rare in patients with contact dermatitis due to cosmetics or topical medicaments.

Adolescent↗
PubMed1996

Sea urchin granuloma of the nail apparatus: report of 2 cases.

The authors report 2 cases of sea urchin granuloma of the nail apparatus resulting in permanent nail deformity. Both patients developed periungual and subungual nodular lesions 1-2 months after sea urchin spine injuries in the Mediterranean sea. The affected nails showed periungual nodules associated with splitting of the nail plate distal to the nodules. Surgical excision of the nail lesions required the removal of a large amount of nail matrix that resulted in permanent nail plate dystrophy. Histopathology revealed typical foreign-body granulomas in the nail dermis.

Adult↗
PubMed1996

Proximal subungual onychomycosis due to Microsporum canis.

A case of proximal subungual onychomycosis due to Microsporum canis in a 36-year-old woman is presented. The onychomycosis involved the left thumb and the little fingernails, with thinning of the nail plate and crumbling of the nail plate surface. A milky-white discoloration of the proximal portion of the left thumbnail was also evident. A 2-mm longitudinal nail biopsy showed a large number of fungal elements in the whole length of the nail plate. Fungal hyphae were more numerous in the ventral nail plate and produced detachment of the superficial nail plate. The nail bed was not invaded by fungal elements and was devoid of inflammatory changes. Proximal subungual onychomycosis is uncommon in immunocompetent individuals but has frequently been described in patients with AIDS. In our patient, in whom the proximal subungual onychomycosis was due to M. canis, there were no clinical or biochemical signs of immunodeficiency. Oral treatment with terbinafine, 250 mg/daily for 2 months, produced clinical and mycological cure.

Adult↗
PubMed1996

Gruppo Italiano Ricerca Dermatiti da Contatto ed Ambientali Italian Multicenter Study of Allergic Contact Photodermatitis: epidemiological aspects.

A total of 1,050 patients with histories and clinical pictures suggestive of photoallergic contact dermatitis were seen. All the patients underwent photopatch tests with haptens proposed by the Gruppo Italiano Ricerca Dermatiti da Contatto plus other substances suggested by each patient's history. Two hundred fifty-nine patients (24.6%) were positive to at least one test substance of the standard series or to substances added. Typical photoallergic reactions were seen in 198 subjects (259 minus 40 toxic photodermatitis to chlorpromazine and 21 to promethazine), which represents 18.8% of the total population. Topical drugs represent the most involved substances in photodermatitis. The incidence in our population was about equal for antimicrobial agents, additives to fragrances, and fragrances themselves. Other allergens found were salicylanilides, whereas sun-screening agents were the fifth group of haptens but with clear-cut relevance. This study is a first attempt to organize the data about results of photopatch tests applied to Italian patients.

Adult↗
PubMed1995

Involvement of CD44 variant isoforms in hyaluronate adhesion by human activated T cells.

The standard, 85-95-kDa form of the hyaluronic acid (HA) receptor CD44 and a number of CD44 mRNA splice variants play important roles in immune responses and tumor metastasis. Variants carrying exon 6 (v6), or 9 (v9) products are transiently expressed on activated human T cells. Here, modulation experiments with specific monoclonal antibodies (mAb) indicate that v6 and v9 are expressed independently on distinct sets of CD44 molecules, and that their combined expression is necessary for HA adhesion. Moreover, the finding that mAb-mediated cross-linking of v6 and v9 promoted cytosolic free Ca2+ mobilization and co-stimulated CD3-triggered T cell proliferation indicates that v6 and v9 possess signaling and effector function activation ability. Finally, HA-mediated signaling appears to be required for variant-dependent adhesion to HA. The observation that soluble HA promoted cytosolic free Ca2+ mobilization indicates that HA-induced Ca2+ mobilization can occur during T cell-HA interaction. Since Ca2+ mobilization was inhibited by pretreatment of cells with an anti-CD44 mAb directed against the HA-binding domain of CD44, CD44 receptors appear to be involved in HA-mediated signal transduction. The requirement of cytosolic free Ca2+ for adhesion is shown by the fact that ionomycin (a Ca2+ ionophore) stimulated, and EGTA (a Ca2+ chelator), inhibited HA adhesion. In addition, cytoskeletal functional activation is required for cell adhesion to HA, since drugs that block actin polymerization, such as cytochalasin B, or actomyosin contraction, such as the calmodulin antagonist W-7, inhibited cell adhesion to HA. As this adhesion is also ADP ribosylation-sensitive, it may involve a GTP-dependent function of CD44v, i.e. ankyrin binding. Our data indicate that there is a functional hierarchy among the CD44 molecules expressed on human peripheral blood T cells and that the splice variants, as compared to the standard form, exhibit a greater HA binding ability which involves CD44-mediated signaling and effector function activation.

Actins↗
PubMed1995

Role of antigenemia assay in the early diagnosis and prediction of human cytomegalovirus organ involvement in AIDS patients.

The role of an antigenemia assay in the diagnosis and prediction of human cytomegalovirus (HCMV) disease in AIDS patients was evaluated. The clinical history of 62 patients with advanced HIV infection from whom a total of 248 blood samples were drawn and tested by the HCMV antigenemia assay was examined retrospectively. Between December 1992 and January 1994, 28 episodes of HCMV disease with organ involvement were recorded; the antigenemia assay was positive in 23 of them (82.1%). In particular, this test was positive in 11 of 12 (91.6%) first episodes and in 3 of 3 (100%) recurrent episodes occurring in patients not receiving maintenance therapy. The same test was positive in 9 of 13 (69.2%) recurrent episodes occurring in patients receiving maintenance therapy. The first occurrence of HCMV disease was always preceded by a positive antigenemia assay 2 and 4 months before diagnosis (in all 7 patients of the 7 for whom a blood sample was available before HCMV disease). A positive antigenemia test result was not always followed by organ involvement, but a high positive cell count (> 100/200,000 polymorphonuclear leukocytes) strongly correlated with the appearance of HCMV disease in the following 1 to 3 months (100% of cases). The antigenemia assay is a useful and reliable indirect method for the diagnosis and prediction of HCMV end-organ disease in severely and persistently immunocompromised AIDS patients.

AIDS-Related Opportunistic Infections↗
PubMed1995

Celiac disease and alopecia areata: report of a new association.

Celiac disease is frequently associated with other autoimmune disorders but has never been reported in association with alopecia areata. In a routine clinical practice, 3 patients with such an association were observed. In one of the patients, celiac disease was diagnosed after the occurrence of malabsorption symptoms. In the youngest patient, a 14-year-old boy, gluten-free diet resulted in complete regrowth of scalp and body hair. A prospective screening program for celiac disease using antigliadin and antiendomysial antibodies was therefore set up in 256 consecutive outpatients with alopecia areata. Three patients, all completely asymptomatic for intestinal diseases, were found to be positive and underwent biopsy. Histological analysis showed a flat intestinal mucosa consistent with the diagnosis of celiac disease. The results show that alopecia areata may constitute the only clinical manifestation of celiac disease and that the association between these two conditions is a real one because the observed frequency of association is much greater than can be expected by chance. It is suggested that antigliadin and antiendomysial antibodies should be included in the work-up of patients with alopecia areata.

Adolescent↗