Navegando por Palavras-chave "time perception"

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    Porphyrin Distribution After Topical Aminolevulinic Acid in a Novel Porcine Model of Sebaceous Skin
    (Wiley-Blackwell, 2009-02-01) Sakamoto, Fernanda Hidemi [UNIFESP]; Tannous, Zeina; Doukas, Apostolos G.; Farinelli, William A.; Smith, Nicholas A.; Zurakowski, David; Anderson, R. Rox; Harvard Univ; Universidade Federal de São Paulo (UNIFESP)
    Background and Objective: Aminolevulinic acid photodynamic therapy (ALA-PDT) depends on drug metabolism into porphyrins. Clinically, ALA-PDT has been used with a wide range of protocols for treating both epidermal and dermal targets, despite limited understanding of porphyrin biodistribution over time. We studied porphyrin accumulation after topical application of ALA in vivo, and also describe the porcine ear as a new animal model to study adnexal glands.Study Design/Materials and Methods: the microanatomy of anterior ear skin of swine was measured. Topical 20% ALA in water/ethanol was applied under occlusion. Biopsies taken after 5, 10, 15, and then every 15 minutes for a total of 3 hours were examined by fluorescence microscopy of frozen sections to assess accumulation and distribution of porphyrins.Results: Porphyrin fluorescence of digital photomicrograph images was not visually apparent until 3045 minutes after application, although quantitative pixel analysis showed a statistically significant increase in epidermal fluorescence only 15 minutes after ALA application. From 30 to 120 minutes, epidermis, hair follicles (HF), and sebaceous glands (SG) became progressively more fluorescent. Eccrine gland fluorescence began to be detected after 30 minutes; SG showed fluorescence starting at 45-75 minutes. Fluorescence in all sites reached maximum intensity from 75 to 180 minutes of incubation. There was a trend for HF and SG to express stronger fluorescence compared with epidermis and eccrine glands.Conclusion: Anterior pig ear skin is microanatomically similar to human sebaceous skin. the time-dependent accumulation of porphyrins in pilosebaceous units and eccrine glands in this model suggests other routes of uptake of topical ALA in addition to the trans-epidermal route. Apparently, time interval between ALA application and light exposure could be optimized for different uses of ALA-PDT. Lasers Surg. Med. 41:154-160, 2009. (C) 2009 Wiley-Liss, Inc.
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    Study of the hearing loss in children and adolescents comparing the periods of 1990-1994 and 1994-2000
    (Elsevier B.V., 2005-06-01) Nobrega, M. de; Weckx, LLM; Juliano, Y.; Universidade Federal de São Paulo (UNIFESP); Univ Santo Amaro
    Introduction: in 1994, a study was performed with 200 children and adolescents suffering from hearing toss. It concluded that the diagnostic confirmation of hearing toss within 2 years of age occurred in just 13% of the cases, although 56% were suspected in that phase. the loss of time of over 2 years between suspicion and confirmation of hearing loss occurred in 42% of the cases.Objectives: the comparison of the main hearing loss etiologies-genetic cause, consanguinity, congenital rubella, meningitis, perinatal. events and unknown causes-in children and adolescents in the periods of 1990-1994 and 1994-2000; comparison of incidence, in mates and females, for each etiology and among the others; comparison of age at the first consultation, for each and among them; and the investigation as to whether the time between suspicion and diagnosis of hearing Loss was different for each etiology and among the others.Methods: During the period of 1990-2000, of the 519 children and adolescents with hearing toss, 442 individuals were selected, in the two moments of the study: 1990-1994 and 1994-2000. the variables used were: sex, age at first consultation, suspected etiotogy and time between suspicion and confirmation of hearing loss.Results: Congenital. rubella, genetic and perinatal. causes, meningitis, consanguinity and unknown causes were responsible for over 80% of all etiologies, in both periods. There were no differences between the sexes in the periods studied. There was no relation among age, sex and etiology. Among the etiologies studied, there were no differences in the lengths of times between suspicion and confirmation of hearing loss, in each period separately. the comparative study showed that congenital rubella, genetic and unknown causes took longer times between suspicion and confirmation of hearing loss, for the period of 1990-1994, as compared with 1994-2000.Conclusions: Congenital rubella remains as an important etiology, as welt post-meningitis deafness. Age at first consultation did not show relationship to the hearing loss etiology nor to sex. Independently of whether the etiology being pre-natal, perinatal or post-natal, congenital or acquired, the length of time between suspicion and confirmation of hearing loss did not differ between the periods studied, separately. (c) 2005 Elsevier Ireland Ltd. All rights reserved.