The major peanut allergen,Ara h 2, functions as a trypsin inhibitor,and roasting enhances this function

BACKGROUND: The widespread use of peanut products, the severity of the symptoms, and its persistence in afflicted individuals has made peanut allergy a major health concern in western countries such as the United States, United Kingdom, and Canada. In a previous study, the authors showed that the allergenic properties of peanut proteins are enhanced as a result of thermal processing. OBJECTIVE: The purpose of this investigation was to determine whether any specific functions are associated with the major peanut allergen, Ara h 2, and whether the functionality of this protein is influenced by processing. An assay was developed and used to assess structure/function changes in Ara h 2 induced by roasting and the effect of these alterations on the allergenic properties of this major peanut allergen. METHODS: A protein domain homology search was used to determine possible functions for Ara h 2. One of the putative functions (protease inhibition) was tested by means of appropriate enzyme assays and protein gel electrophoresis. Circular dichroism was used to compare the structural properties of Ara h 2 purified from raw and roasted peanuts. RESULTS: Ara h 2 purified from peanuts is homologous to and functions as a trypsin inhibitor. Roasting caused a 3.6-fold increase in trypsin inhibitory activity. Functional and structural comparison of the Ara h 2 purified from roasted peanuts to native and reduced Ara h 2 from raw peanuts revealed that the roasted Ara h 2 mimics the behavior of native Ara h 2 in a partially reduced form. CONCLUSIONS: The data indicate that thermal processing might play an important role in enhancing the allergenic properties of peanuts. Not only has it previously been shown to affect the structural and allergic properties of peanut proteins but also, for the first time, the functional characteristics of an allergen. These structural and functional alterations are likely to influence the allergenicity of peanuts.     

Screening 34 Peanut Introductions for Allergen Content Using ELISA

Peanut is one of the most allergenic foods and reports of accidental ingestion of peanuts in unsuspected food are increasing. No information is available on the allergen content of peanut germplasm grown commercially and used in the food and confectionery industry. The objectives of this study were: (1) to determine the allergen contents of 34 peanut introductions (PI); and (2) to identify naturally occurring allergen-free and/or low or hypoallergenic peanuts germplasm. A basic ELISA protocol was utilized to detect the presence of antigens in the peanut lines using a pool of human sera from patients with documented history of peanut allergy. Two naturally occurring low, or hypo-allergenic germplasm were identified as PI 261942 and PI 338386. Both are Valencia market types with total allergen content significantly lower (P ≤0.05) than that of PI 119880 (0.550), PI 119876 (0.415) and PI 118991 (0.410) three Valencia market types and PI 262111 (0.485), a Virginia market type. No allergen-free PI was found. Allergen content of peanut lines from Bolivia and Paraguay were significantly (P ≤0.05) different to those from Venezuela. No significant difference was observed in the allergen content of the four market types.     

Moraxella catarrhalis--infected alveolar epithelium induced monocyte recruitment and oxidative burst

The recruitment of monocytes appears to be a crucial factor for inflammatory lung disease. Alveolar epithelial cells contribute to monocyte influx into the lung, but their impact on monocyte inflammatory capacity is not entirely clear. We thus analyzed the modulation of monocyte oxidative burst by A549 and isolated human alveolar epithelial cells. Epithelial infection with Moraxella catarrhalis induced monocyte adhesion, transepithelial migration, and superoxide generation, whereas stimulation with lipopolysaccharide, tumor necrosis factor-alpha, interleukin-1beta, or interferon-gamma induced adhesion or transmigration, but failed to initiate monocyte burst. The effect of microbial challenge was mimicked by phorbol myristate acetate and inhibited by the protein kinase C inhibitor bisindoylmaleimide. Furthermore, evidence for a role of platelet-activating factor-signaling in monocytes is presented. Monocyte burst was neither induced by supernatant nor affected by fixation of A549 cells, excluding the contribution of epithelium-derived soluble factors but emphasizing the mandatory role of intercellular contact. The employment of blocking antibodies, however, denied a role for the adhesion molecules intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, or CD11b/CD18 and CD49d/CD29. In essence, infection of alveolar epithelial cells with M. catarrhalis might amplify the inflammatory capacity of invading monocytes eliciting their superoxide production. The epithelial response to this microbial challenge thus clearly differed from that to proinflammatory cytokines.     

Myocardial damage in falciparum malaria detectable by cardiac troponin T is rare

OBJECTIVES: To estimate the prevalence of myocardial damage in falciparum malaria by serum concentration of cardiac troponin T. METHODS: Retrospective study of stored sera and patient files; assessment of acute myocardial damage by serum concentration or activity of cardiac troponin T, creatine kinase, creatine kinase MB and myoglobin and by routine electrocardiography. RESULTS: A total of 161 patients with falciparum malaria were included in the study; troponin T was elevated in one case (0.6%), no CK-MB elevations were found, myoglobin was elevated in 10 of 161 patients (6.2%), all of whom were elderly and had concomitant elevated serum concentration levels of cystatin C; ECG abnormalities were seen in 23 patients. CONCLUSION: Assessed by troponin T, myocardial damage in falciparum malaria is rare.     

Comparison between the psychophysical scale methods for magnitude estimation and category estimation of nurses' social perception

This experiment aimed to rank nurses' social perception through the magnitude and category estimation methods. Study participants were high school and university students, active and retired professionals in the areas of medicine, psychology, nursing and dentistry. The results showed: (1) the characteristics neat, responsible, clean, careful and efficacious occupied the first positions in terms of nurses' social perception; whereas the characteristics useless, dishonorable, irresponsible and hateful occupied the last positions in the scales obtained by the two direct psychophysical methods, and (2) the non-metric social perception continuum has prosthetic characteristics.