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Biomedical subjects

L Karla Arruda

Publications and source records attributed to L Karla Arruda.

8 recordsLinked to original sources
PubMed2005

Cockroach allergens.

Cockroaches produce several potent allergens associated with sensitization and the development of asthma. Many of these allergens have been cloned and produced as biologically active recombinant proteins. Three-dimensional structure and molecular modeling, in addition to studies on the biological functions of these proteins in the cockroach, have provided new insights into the ability of these allergens to cause immunoglobulin E antibody responses. Recent studies have pointed to a potential role of recombinant cockroach allergens for diagnosis and the development of novel therapeutic strategies that may benefit cockroach-allergic patients.

Allergens↗
PubMed2005

Risk factors for asthma and atopy.

PURPOSE OF REVIEW: The aim of this article is to provide information on risk factors associated with the development of atopy and asthma in childhood. RECENT FINDINGS: Several gene polymorphisms have been associated with susceptibility to asthma and allergy; complex gene-environmental interactions, however, appear to play a key role in the development of the disease. Early life sensitization to aeroallergens, presence of atopic dermatitis or allergic rhinitis, maternal smoking during pregnancy and children's environmental exposure to tobacco smoke, lower respiratory tract infections with respiratory syncytial virus and potentially with other viruses including rhinovirus and metapneumovirus, exposure to air pollutants, several perinatal factors other than maternal smoking, are among factors associated with an increased risk for development of chronic asthma. SUMMARY: The prevalence of asthma and allergic diseases is increasing progressively. Those who are involved in the care of young children should be prepared to recognize risk factors for development of these diseases and to appreciate the role of gene-environment interactions. Preventive measures established at an early age may modify the natural history of asthma and other allergic diseases.

Air Pollution↗
PubMed2005

Immunologic responses to common antigens in helminthic infections and allergic disease.

PURPOSE OF REVIEW: It is estimated that over 1 billion individuals are infected with helminth parasites worldwide. Epidemiologic studies have pointed to a protective role of helminthic infections in the development of allergy and asthma; however, evidence for this inverse association has not been consistently established. The focus of this review is to discuss the potential role of shared antigens between parasites and environmental allergens in modulating allergic immune responses, specifically tropomyosin. RECENT FINDINGS: Tropomyosin has been identified as a highly conserved molecule in invertebrates. In populations exposed concomitantly to mites, cockroach, Ascaris, and shrimp and other crustaceans and mollusks, IgE antibody responses to tropomyosin are found in over 50% of individuals. Evidence suggests that IgE cross-reactivity to tropomyosin has clinical relevance. SUMMARY: Mechanisms underlying the immunomodulatory effects of parasites in allergy and asthma remain poorly understood. Identification of molecules in intestinal parasites, particularly Schistosoma mansoni and Ascaris lumbricoides, associated with protection from or promotion of allergy and asthma, could provide the basis for novel forms of treatment or prevention of these diseases. Prospective studies will be necessary to clarify the role of tropomyosin and other parasite antigens shared with inhalant or food allergens in the development of allergic diseases.

Ancylostomatoidea↗
PubMed2005

A prospective study of wheezing in young children: the independent effects of cockroach exposure, breast-feeding and allergic sensitization.

The objective of this study was to evaluate risk factors for persistent wheezing in a group of 2-4-year-old children after an index-wheezing episode in infancy. Eighty infants who had been seen at the Emergency Department for an episode of acute wheezing were followed for 2 yr in this prospective study. Caregivers completed a questionnaire, and children underwent clinical evaluation and skin prick testing 2 yr following the index-wheezing episode. Detection of respiratory viruses and analysis of exposure to major indoor allergens were carried out at enrollment. Immunoglobin E antibodies were measured at the beginning of the study and at the end of follow-up, using the CAP system. Logistic regression analysis was performed to identify factors associated with persistent wheezing. Seventy-three children (44 boys) completed the study. After 2 yr, 38 (52%) reported three or more wheezing episodes in the past 12 months (persistent wheezers). Independent risk factors for persistence of wheezing were allergic sensitization and exposure to cockroach allergen in the kitchen. Breast-feeding for at least 1 month was a protective factor. A strong association between allergic sensitization and persistence of wheezing was found in a group of very young children living in a subtropical area.

Allergens↗
PubMed2004

Exposure to indoor allergens in homes of patients with asthma and/or rhinitis in southeast Brazil: effect of mattress and pillow covers on mite allergen levels.

BACKGROUND: Exposure and sensitization to indoor allergens have been associated with the development of asthma and other allergic diseases in many parts of the world. It is important to establish the degree of exposure, and to evaluate whether allergen control measures are effective in a particular area. METHODS: Concentrations of major allergens of mites, cockroach, cat and dog were measured in dust samples from homes of 24 mite-allergic patients living in Ribeirão Preto, Brazil. Allergen concentrations were quantitated by monoclonal antibody-based ELISA. Mite-impermeable mattress and pillow covers were applied to beds in the homes of 19 of the 24 patients, and group 1 mite allergen levels were measured 1 and 6 months following intervention. RESULTS: Patients were exposed to high concentrations of mite allergens in their homes. 87.5% of the homes presented concentrations of group 1 allergens >10 microg/g of dust in at least one site. Cockroach allergen concentrations were low in most samples. Dog allergen concentrations were significantly higher in homes with dogs as compared to those without dogs. Mean concentrations of cat allergen were 0.1 microg/g. Mite allergen concentrations in bedding samples dropped from 24 microg/g at baseline to 0.9 and 1.0 microg/g, respectively, 1 and 6 months following encasement of mattresses and pillows. CONCLUSIONS: Significant mite allergen reduction can be achieved in an area of high degree of exposure to mite allergens. Further studies evaluating the effect of this reduction on symptoms and airway inflammation will be necessary to establish the effectiveness of mite avoidance measures in our area.

Adolescent↗
PubMed2004

Risk factors for wheezing in a subtropical environment: role of respiratory viruses and allergen sensitization.

BACKGROUND: Risk factors for acute wheezing among children in subtropical areas are largely unknown. OBJECTIVE: To investigate the role of viral infections, allergen sensitization, and exposure to indoor allergens as risk factors for acute wheezing in children 0 to 12 years old. METHODS: One hundred thirty-two children 0 to 12 years of age who sought emergency department care for wheezing and 65 children with no history of wheezing were enrolled in this case-control study. Detection of respiratory syncytial virus antigen, rhinovirus and coronavirus RNA, adenovirus, influenza, and parainfluenza antigens was performed in nasal washes. Total IgE and specific IgE to mites, cockroach, cat, and dog were measured with the CAP system. Major allergens from mites, cockroach, cat, and dog were quantified in dust samples by ELISA. Univariate and multivariate analyses were performed by logistic regression. RESULTS: In children under 2 years of age, infection with respiratory viruses and family history of allergy were independently associated with wheezing (odds ratio, 15.5 and 4.2; P = .0001 and P = .008, respectively). Among children 2 to 12 years old, sensitization to inhalant allergens was the major risk factor for wheezing (odds ratio, 2.7; P = .03). High-level allergen exposure, exposure to tobacco smoke, and lack of breast-feeding showed no association with wheezing. CONCLUSIONS: Some risk factors for wheezing previously identified in temperate climates were present in a subtropical area, including respiratory syncytial virus infection in infants and allergy in children older than 2 years. Rhinovirus was not associated with wheezing and did not appear to be a trigger for asthma exacerbations.

Allergens↗
PubMed2002

Daycare centers and schools as sources of exposure to mites, cockroach, and endotoxin in the city of São Paulo, Brazil.

BACKGROUND: Public places, including schools, have been identified as sources of exposure to allergens derived from mites, cockroach, cat, and dog and to endotoxin. OBJECTIVES: The purposes of this study were to assess and compare exposure to allergens and endotoxin in 4 types of public child-care facilities in Brazil and to investigate whether the presence of children and the performance of cleaning procedures could have an influence on allergen and endotoxin levels. METHODS: We have analyzed dust from bedding, floors, chairs, and tables of daycare centers (DCs), preschools, kindergartens, and elementary schools (ESs). Major allergens from mites, cockroach, cat, and dog were quantitated by means of ELISA, and endotoxin content was determined by using the Limulus Amebocyte Lysate assay. RESULTS: Group 1 mite allergens were greater than 2 microg/g in 67% of DC and preschool samples and in 8.9% and 2.2% of kindergarten and ES samples, respectively. The presence of bedding in DCs and preschools accounted for increased levels of mite allergens in these settings. Levels of Bla g 1 were higher in ES floors compared with those found in DC and preschool floors. Low levels (<1 microg/g) of Fel d 1 e Can f 1 were found in most samples. Levels of endotoxin in DCs and preschools were 3 times higher than in ESs. CONCLUSIONS: DCs and schools in Brazil should be considered as important sources of exposure to dust mites and cockroach allergens and to endotoxin. Recommendations for mite allergen avoidance should include appropriate care of bedding in DCs and preschools.

Adolescent↗