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Biomedical subjects

M de Luca

Publications and source records attributed to M de Luca.

12 recordsLinked to original sources
PubMed1999

Incidence of cockroach allergy in atopic Italian children.

BACKGROUND: Recent studies suggest that sensitization to cockroach allergens is common in urban areas and highlight the importance of cockroach allergens as a risk factor for asthma. OBJECTIVE: To elucidate the prevalence of cockroach allergy in atopic Italian children and to evaluate the correlation between cockroach allergens and other major indoor allergens. METHODS: Four hundred eighty two children with at least one positive skin test response to a common allergen and with personal history of atopic diseases, were investigated. A questionnaire was administered in order to obtain data on epidemiologic and clinical characteristics of the population. Skin tests to 24 common allergens (including extracts of two cockroach species) were carried out and serum total and cockroach specific IgE were evaluated. RESULTS: 61/482 (12.7%) children had positive skin test to cockroach extracts. Among them the frequency of children living in urban areas was higher (P < .05). In addition, a significant correlation between results of skin tests to cockroach and mite allergens was observed (P < .009). No correlation between cockroach allergy and the clinical characteristics of the study population was found. CONCLUSIONS: The results show that cockroach allergy affects a small portion of atopic Italian children and suggest that it is related with living in urban areas and with sensitization to other indoor allergens, such as dust mite.

Adolescent↗
PubMed1993

Fish allergy in children.

Fish allergy is a relevant clinical problem in fish eating and/or processing communities but, because of the technologic advances of the preserved food industry, it may now be said to be a worldwide problem. Among 558 consecutive children referred for atopic diseases, 25 (4.48%) subjects skin test- and RAST- positive to cod were recorded and we extrapolated that about 4-5/1000 children have allergy to cod in our areas. As a group, children with cod allergy seem to manifest a higher atopic condition and more severe clinical manifestations. IgE level z-score (mean +/- SD) was significantly (P < .001) higher in 68 cod-positive children (14.27 +/- 3.87) than in 533 children positive to other inhalant and/or food allergens (8.12 +/- 4.06). In spite of a smaller median age (59 months), cod-positive children had a higher frequency of asthma (41/68 = 60.2%) than children with other allergies, and age at the onset of asthma was significantly (P < .001) younger in the former (32 months) than in the latter (41 months) subjects. In addition, urticaria-angioedema was more frequently recorded in cod-allergic children (23/68 = 33.8%) than in patients with allergy to inhalants (26/410 = 6.3%; P < .01), inhalants and foods different from cod (11/74 = 14.8%; P < .01), or foods different from cod (6/49 = 12.2%; P < .01). The male:female ratio in cod-allergic children (3.53) was significantly higher than that observed in children with allergy to inhalants (1.78; P = .037) or foods (0.68; P < .0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

"HepG2/erythroid/brain" type glucose transporter (GLUT1) is highly expressed in human epidermis: keratinocyte differentiation affects GLUT1 levels in reconstituted epidermis.

In mature animals, the "HepG2/erythroid/brain" glucose transporter isoform (GLUT1) appears to be expressed at the highest levels at blood tissue barriers; however, these levels may still be lower than the levels of expression seen in fetal tissues. Also, glucose transporters might serve as water channels. Therefore, we decided to investigate GLUT1 expression in human epidermis, a very active tissue, in terms of metabolism, even if not directly vascularized. We found GLUT1 transcripts in human skin and demonstrated, by immunohistochemistry, that GLUT1 protein is highly expressed in the basal layer and, to a lower extent, in the immediately suprabasal layer of the epidermis. This distribution pattern suggested that GLUT1 expression is affected by keratinocyte differentiation. To investigate this possibility, we used human epidermis reconstituted in culture. Our culture system allows the reconstruction of a stratified squamous epithelium which has been successfully grafted onto patients presenting large skin defects. Human keratinocytes have been cultured under conditions which allow a modulation of cellular differentiation and stratification. We observed that (i) GLUT1 expression is 4-6-fold higher in "stem-like" basal cells than in large, differentiated keratinocytes; (ii) culture conditions causing cell differentiation reduce GLUT1 expression, while conditions which minimize either differentiation or stratification of keratinocytes enhance GLUT1 expression. Finally, we found that IGF-1 and insulin, probably acting through the IGF-1 receptor, increase GLUT1 expression and stimulate glucose transport activity in epidermis reconstituted in culture. In conclusion, our data demonstrate that GLUT1 is highly expressed in the basal layers of human epidermis and that its expression is modulated by keratinocyte differentiation.

Brain↗
PubMed1991

Periodontal regeneration procedures may induce colonization by glycocalyx-producing bacteria.

Sixteen patients that underwent periodontal regeneration procedures by implantation of Goretex membranes were studied to evaluate the microbiota that colonized membranes. The microbiological follow-up showed that colonization was principally due to opportunist gram-negative glycocalyx-producing bacteria. The comparison of the microbial flora of treated and untreated sites showed the influence of surface characteristics on the quality of the resident microbiota. These findings suggest the necessity for developing efficient prohylactic protocols for these cases.

Dental Plaque↗
PubMed1990

Evidence that human oral epithelium reconstituted in vitro and transplanted onto patients with defects in the oral mucosa retains properties of the original donor site.

Normal human skin--derived keratinocytes cultured in vitro reconstitute a stratified epidermis suitable for grafting onto burn patients and patients with skin defects such as giant nevi or chronic leg ulcers. In vitro experiments and long-term studies of patients receiving cultured epidermis autografts on muscular fascia suggest that skin keratinocytes possess an intrinsic site specific differentiation program that is fully expressed only when the reconstituted epidermis is transplanted in vivo to different body sites. In this study we cultivated for the first time palate-derived epithelial cells that were able to reconstitute a palatal epithelium. We also demonstrate that this epithelium can be successfully transplanted onto patients presenting lack of adherent keratinizing gingival mucosa and is able, in a relatively short time, to fully express the differentiation program typical of the original donor site. The possibility of obtaining large quantities of cultured epithelium, able to retain properties of the original donor site, starting from 1-3-mm2 biopsies, could prove extremely useful in the reconstructive surgery of the mouth and of other mucosal body areas.

Epithelium↗
PubMed1986

Monoclonal antibody studies defining the origin and properties of autoantibodies in Graves' disease.

The present report summarizes experiments with monoclonal antibodies to the TSH receptor. The data provide further insight into the TSH receptor structure and into the basis of autoimmune antibodies implicated in the pathogenesis of Graves' disease. They resolve many clinical questions and provide new approaches to enhance our understanding of autoimmune disease. In one new approach, it has been noted that the 11E8 TBIAb can precipitate the phosphorylated beta subunit of the insulin and IGF1 receptor. This cross-reactivity or recognition of determinants adjacent to the TSH receptor may not be random. Insulin, IGF1, alpha 1 adrenergic, and TSH receptors have been linked to a synergistic cascade response system of the thyroid involving growth, thyroglobulin biosynthesis, iodination of thyroglobulin, and thyroid hormone formation. Future studies with the monoclonals may help unravel this cascade system and its regulatory relationships, along with the relationships between autoimmune thyroid disease and autoimmune diseases of other organs.

Antibodies, Anti-Idiotypic↗
PubMed1982

[Inhibition of the biosynthesis of thyroglobulin with propranolol in the rat].

Thyroglobulin biosynthesis was studied in thyroid glands of rats treated during 30 days with a daily dose of propranolol, a non-selective beta-adrenergic blocking drug. Studies were carried out by extraction of soluble proteins from homogenates after incubation of the glands in presence of [3H]-4,5-L-leucine and [3H]-D-1-galactose. Thyroglobulin 19S, 12S and 4-8S soluble proteins were separated and identified by ultracentrifugation in a saccharose gradient. The glands of rats treated with propranolol showed a decreased amount of soluble proteins as well as a decreased incorporation of [3H] labeled markers. 19S thyroglobulin is poorly represented, but very large amounts of the 12S monomer are present; this suggests an impairment in the dimerization of the 12S subunit, absent in normal controls. This impairment could be due to a structure modification. Propranolol reduces the biosynthesis of thyroglobulin in thyroid gland as well as the formation of T3 from T4 in peripheral tissues; its therapeutical use against thyrotoxicosis is thus justified. The study of its action on the dimerisation of the 12S subunit could be of interest to clear the mechanism of thyroglobulin biosynthesis.

Animals↗
PubMed1982

[Inhibition of the biosynthesis of thyroglobulin in the thyroid gland of rats by isoniazid].

Groups of rats have been treated for one month with a daily dose of 50 mg/kg of body weight/day of isoniazide a product used therapeutically in man against tuberculosis. The animals submitted to this experiment showed an increase of thyroid weight (39%) and a decrease of its content in water soluble proteins, including thyroglobulin and precursors. These proteins have been labeled in vitro by [3H]-4,5-L-leucine and by [3H]-galactose, by incubation of isolated glands during 4 h in a medium containing this labeled marker. The decrease of thyroglobulin-like proteins was of 20-37% for [3H]-D-1-galactose, labeled fraction and of 46-53% for the [3H]-leucine labeled fraction. Two thirds of the radioactive protein sedimented by ultracentrifugation in a sucrose gradient were present in a 12S monomer of thyroglobulin. This suggests an impairment of biosynthesis of 19S thyroglobulin, in which two of the subunit are associated. Under experimental conditions adopted this 19S protein was labeled by [3H]-leucine, but not by [3H]-galactose. Two other antituberculous agents studied, ethambutol and rifamizine, exerted not the same effects on thyroid gland in rats. Therefore a control of thyroid function appear to be necessarily only in man treated by isoniazine.

Animals↗
PubMed1982

Pemphigus provoked by D(-)penicillamine. An experimental approach using in vitro tissue cultures.

We present the results of our experiments with in vitro tissue cultures of normal human skin, carried out in order to clarify the mechanism(s) by which D(-) penicillamine provokes pemphigus. Various concentrations of D(-) penicillamine were added to the culture medium and produced acantholytic splitting, closely similar to control lesions produced by pemphigus serum, whereas no lesions occurred in controls cultured without the drug. This suggests to us that the pemphigus of D(-)penicillamine is due to biochemical mechanisms and is not mediated by antibodies. Integrating our data with those of previous clinical and experimental studies on idiopathic pemphigus vulgaris leads us to think that the pemphigus antigen(s) might be present in certain structures of the cell membrane of epithelial cells, which are linked with the initial phases of keratin differentiation.

Adult↗