Biomedical subjects

P Barranco

Publications and source records attributed to P Barranco.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Importance of albumin in cross-reactivity among cat, dog and horse allergens.

Different allergenic proteins have been involved in cross-reactivity among animals. Albumins seem to be cross-sensitizing allergenic components. The aim of this study was to assess the importance of albumin as a cross-reactive allergen in patients sensitized to cat, dog and horse. One hundred and seventeen patients sensitized to cat were tested for IgE reactivity using skin prick tests and RAST assays with cat, dog and horse hair/dander extracts and their purified albumin extracts. RAST-inhibition studies were carried out to assess cross-reactivity among cat, dog and horse and among their purified albumins. It was found that 22% of patients exhibited specific IgE to cat albumin; 41% of patients sensitized to cat were also sensitized to dog and horse. Out of these patients, 21% had IgE to three albumins and 17% to two. Reciprocal inhibitions were observed among cat, dog and horse albumins and also among cat, dog and horse hair/dander extracts, using in the latter experiment sera from patients not sensitized to albumins. IgE binding to horse extract was inhibited 30% by its homologous albumin and IgE binding to cat and dog extracts in almost 15% by their respective albumins. It was concluded that albumins from these three animals share some epitopes that account for the cross-reactivity observed in around one-third of patients sensitized to cat, dog and horse. Nevertheless, more than 50% of specific IgE that cross-reacts among these three animals is directed to allergens other than albumin.

Albumins↗

PubMedDate not supplied

Booster responses in the study of allergic reactions to beta-lactam antibiotics.

The observation of negative skin and challenge tests to beta-lactams in some patients with prior histories of reactions to these antibiotics led us to develop a protocol ("booster study") which systematically included the performance of skin and challenge tests to beta-lactams ten to thirty days after the study to confirm the negative results. From a total of 430 patients who came to our outpatient clinic because of a reaction to a beta-lactam or unknown antibiotic, 249 completed the study. Out of the patients who completed the second phase, or "booster study," the results were positive in the first phase, or conventional study in 42 patients, and negative in 207. The booster study was negative in 197 patients (95 percent) and positive in ten patients (5 percent). Skin tests were positive in 5 of them (penicilloyl-polylysine: 5; benzylpenicillin: 3; amoxicillin: 2; minor determinant mixture: 1), and 5 patients developed an allergic reaction after rechallenge (benzylpenicillin: 4; amoxicillin: 1). One patient with both negative skin tests and amoxicillin oral challenge in the booster study developed an immediate generalized urticaria with the oral intake of amoxicillin one month later at home; skin tests became positive at that moment. The negative results in the first phase of the study and the development of positive results in the second phase could be due to the existence of an immunological amnestic reaction or to sensitization after reexposure to beta-lactams in the diagnostic procedures.

Adolescent↗

PubMedDate not supplied

Two cases of specific adverse reactions to systemic corticosteroids.

Although true allergic reactions due to systemic corticosteroid therapy are not frequent, they should be kept in mind since allergic reactions to this kind of therapy are possible. We report two cases of specific adverse reactions resulting from systemic corticosteroid therapy which were diagnosed by provocation tests. The corticosteroids involved in each case were paramethasone and betamethasone, and methyl-prednisolone in both of them. Additives and other corticosteroids were studied by skin tests and challenges, with negative results. The structures of paramethasone and betamethasone are similar, with a 16 carbon methyl group in both, and with a fluoride in the alpha position of the 6 carbon in paramethasone, and a fluoride in the beta position of the 9 carbon and a 6 carbon methyl group in betamethasone. Methyl-prednisolone differs from that of other corticosteroids in its 6 carbon methyl group. We report two cases of specific adverse reactions caused by corticosteroids. Positive challenge tests showed a possible immunologic hypersensitivity mechanism in both cases. The patients' reactions demonstrated cross-reactivity between methyl-prednisolone and the corticosteroids having a 16 carbon methyl group, and fluoride or methyl radicals on the 6 carbon.

Adrenal Cortex Hormones↗