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F Ferreira

Publications and source records attributed to F Ferreira.

116 records · Page 7Linked to original sources
PubMedDate not supplied

Cross-reacting allergens in tree pollen and pollen-related food allergy: implications for diagnosis of specific IgE.

BACKGROUND: A number of recombinant allergens are by now constituents of devices that can be routinely used for the detection of specific IgE. Therefore, the results of diagnostic procedures using conventional allergen extracts can be compared with those employing selected recombinant allergens. METHODS: Thirty-four sera from patients allergic to birch pollen were tested with the standard t3-CAP and rBet v 1a- and rBet v 2-CAP. cDNA was prepared by RT-PCR using primers according to the N terminus of purified allergens. Expression cDNA libraries were screened with IgE from selected patients. RESULTS: Twenty-four patients allergic to birch pollen showed the same RAST class with t3 as with rBet v 1a; 8 patients differed within 1 RAST class. In addition, 3 patients showed RAST class 3 with rBet v 2. Besides Bet v 1 and Bet v 2, 3 allergens from celery and avocado belonging to highly conserved protein families were cloned and sequenced. CONCLUSIONS: rBet v 1a can be expected to represent an excellent tool for the diagnosis of patients allergic to birch pollen in Central, Northern, and Eastern Europe. Still, a much higher number of patients has to be tested. For their high degree of conservation, further protein families have to be identified to explain cross-reactivities of birch pollen allergens other than Bet v 1 and Bet v 2 with, e.g., allergens from vegetable food.

Allergens↗
PubMedDate not supplied

Enolases are highly conserved fungal allergens.

BACKGROUND: Lack of knowledge of the identity of fungal allergens still is a major obstacle for improvement of diagnosis and therapy of allergies to moulds. We have therefore further analyzed the allergens of the two moulds, Alternaria alternata and Cladosporium herbarum and found that enolases (EC 4.2.1.11) are major allergens, at least of the two fungal species just mentioned. METHODS: The enolases of Alternaria and Cladosporium were cloned from cDNA libraries constructed from vegetative cells of the two moulds by immunological screening with sera from selected patients allergic to the moulds. The two enolases were expressed as recombinant nonfusion proteins and used for determination of the incidence of allergy to enolase among a cohort of patients. RESULTS: Sequencing of the two enolases showed very close relationships with other known fungal enolase sequences. Competition experiments using immunoblots of the recombinant nonfusion proteins showed nearly complete identity of the epitopes on both enolases. Serum from a patient reactive to Cladosporium enolase reacted equally well with the enolases of Alternaria, Saccharomyces and Candida. About 50% each of the sera from patients reactive to Cladosporium and Alternaria were strongly reactive to the recombinant enolases. CONCLUSIONS: Enolases are therefore considered to be highly conserved major fungal allergens.

Allergens↗
PubMedDate not supplied

Isoforms of atopic allergens with reduced allergenicity but conserved T cell antigenicity: possible use for specific immunotherapy.

BACKGROUND: We analyzed the T cell activation potency and the IgE-binding properties (allergenicity) of nine isoforms of Bet v 1, the major allergen of birch pollen. METHODS: The capacity of recombinant Bet v 1 isoforms to bind serum IgE from allergic patients was evaluated by immunoblot experiments and skin prick tests. The potency of Bet v 1 isoallergens to activate T lymphocytes from birch-pollen-allergic patients was assayed using allergen-specific T cell clones. RESULTS: According to their ability to bind IgE from allergic patients in immunoblot experiments, Bet v 1 isoforms can be grouped into high-IgE-binding molecules and molecules with low/no IgE-binding activity. Representatively, isoform d was used in skin tests. Skin prick tests revealed no potency of this isoform to induce wheal and flare reactions in the skin of birch-pollen-allergic individuals. In contrast, isoform a and natural Bet v 1 displayed high allergenicity in vivo. On the other hand, Bet v 1 isoform d (low allergenicity) displayed significant higher T cell activation potency when compared to isoform a (high allergenicity). CONCLUSION: Based on these findings, we propose a new form of specific immunotherapy using hypoallergenic recombinant allergen isoforms.

Allergens↗
PubMedDate not supplied

[Epidemiologic study of bovine and human leptospirosis in eastern Brazilian Amazon].

The seroprevalence study for leptospirosis in bovines and humans was realized in family holder farms along the Transamazon Highway. The prevalence of bovine leptospirosis was 97% [90.9 - 99.5%] of farms with at least one positive animal according to microscopic agglutination test for the leptospirosis diagnostic. In 61.2% of the tested herds, the serovar hardjo was the most common, followed by the serovar bratislava (9%) and the serovar shermani (4.5%). The serologic prevalence of leptospirosis in humans was 32.8% [23.4 - 43.5%] in family groups with at least one positive individual according to microscopic agglutination test for the leptospirosis diagnostic. In 9% of family groups, the serovar bratislava was the most common, while serovar hardjo and grippotyphosa accounted for 6% and 4.5%, respectively. The impact of these results is discussed in relation to animal production and public health. Suggestions have been proposed in order to improve the situation in the region.

Animals↗
PubMedDate not supplied

[Surgical removal of pulmonary metastasis: prospective study in 182 patients].

PURPOSE: The present study evaluates the results of surgical treatment of lung metastases, as well as attempts to identify subgroups of patients who would benefit the most from the operation. CASE AND METHODS: This is a prospective analysis of patients with history of neoplasia, submitted to resection of pulmonary nodules, with the diagnosis or suspicion of metastases. The 182 patients were operated upon through a lateral thoracotomy. RESULTS: The patients submitted to pulmonary resection for suspected metastases showed no malignant tissue in 34 patients (18.6%), and in six patients (3.2%) were diagnosed a second lung primary tumor. Overall survival of the patients was 28% at 56 months, and disease-free survival was 9%. Multivariate analysis showed that disease free interval (p = 0.002), complete resection (p = 0.039), and number of malignant nodules resected (p = 0.016) significantly affected overall survival. Disease-free survival was affected only by complete resection (p = 0.0001) and number of malignant nodules resected (p = 0.004). CONCLUSION: Resection of pulmonary metastasis improve survival in a selected group of patients. More studies are necessary to define the value of other therapies in the results of survival in resected pulmonary metastasis.

Disease-Free Survival↗
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[Medullary and intracranial metastases of myxopapillary ependymoma].

After a brief introduction about the clinical, histological and therapeutic characteristics of myxopapillar spinal ependymoma of cone medullar and filum terminale, three cases with medullar and intracranial seeding of myxopapillar spinal ependymoma are retrospectively reviewed. Surgical resection was total in the child and partial in the adult cases and the histological results were myxopapillar. The diagnosis was made by CT and MRI between 1-2 months before surgical treatment. No extra-neural tumour was found. The mechanisms and factors that influence the seeding of this type of tumour are discussed. The most important literature is reviewed and the cases discussed. The authors stress the importance of surgery on prognosis and the need of an MRI of the whole neural-axis, particularly in children, and subtotal exeresis in adults.

Adult↗
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Synaptosomal GABA release as influenced by valerian root extract--involvement of the GABA carrier.

The effect of an aqueous extract obtained from the roots of Valeriana officinalis was investigated on the uptake and release of GABA in synaptosomes isolated from rat brain cortex. Aqueous extract of valerian inhibited the uptake and stimulated the release of [3H]GABA, either in the absence or in the presence of K+ depolarization. The release was Na(+)-dependent and independent of the presence of Ca2+ in the external medium. It is concluded that valerian extract releases [3H]GABA by reversal of the GABA carrier, which is Na(+)-dependent and Ca(2+)-independent. This increase in [3H]GABA release appears to be independent from Na(+)-K(+)-ATPase activity and the membrane potential.

Amino Acids↗